Association of low concentration of vitamin C and low fresh fruits and vegetables consumption with cardiovascular diseases in type 2 diabetes. Running title: vitaminC and cardiovascular diseases in type 2 diabetes

Association of low concentration of vitamin C and low fresh fruits and vegetables consumption with cardiovascular diseases in type 2 diabetes. 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Running title: vitaminC and cardiovascular diseases in type 2 diabetes Anna Toffalini, Nicolò Vigolo, Elisa Paviati, Matteo Gelati, Elisa Danese, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3955661/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose Vitamin C is a fundamental antioxidant that plays roles in important metabolic processes. Patients with type 2 diabetes are exposed to oxidative stress as a consequence of an increase in ROS production. The aims of the present study were to estimate the prevalence of vitamin C deficiency in ambulatory patients with type 2 diabetes, to study the relationship of vitamin C levels and cardiovascular diseases and to correlate the fresh fruits and vegetables consumption with vitamin C levels and the presence of cardiovascular diseases. Methods In 200 ambulatory patients with type 2 diabetes, vitamin C levels, with HPLC, and consumption of fresh fruits and vegetables, with a dedicated questionnaire, were measured. All other laboratory variables were measured with standard methods. Association between vitamin C and cardiovascular diseases was assessed using multivariable logistic regression analysis. Results Vitamin C deficiency was found in 12.2 % of subjects. Vitamin C levels and consumption of fresh fruits and vegetables were lower in subjects with cardiovascular diseases. Fresh fruits and vegetables intake were associated with higher levels of vitamin C. In multivariable analysis, vitamin C was independently associated with cardiovascular diseases. Conclusion In conclusion, our study seems to suggest that vitamin C might have an inverse relation with cardiovascular diseases. The intake of vitamin C from fresh fruits and vegetables may have a protective role. diabetes antioxidant vitamin C fresh fruit diet Figures Figure 1 INTRODUCTION It has been reported that nutrition and diet may account for approximately 45% of all adult cardiometabolic deaths in the United States [ 1 ]. Micronutrients are important components of a healthy diet [ 2 , 3 ], among these vitamin C is an essential required component [ 4 ]. Vitamin C is a fundamental antioxidant that plays roles both as co-factor for many important metabolic processes and a non-enzymatic quencher for free radicals otherwise capable of modifying cellular macromolecules [ 5 ]. Patients with type 2 diabetes are exposed to oxidative stress as a consequence of an increase in ROS production and lipid peroxidation [ 6 ]. Oxidative stress is supposed to play a physiopathological role in causing cardiovascular diseases, that are the main cause of morbidity and mortality in type 2 diabetes [ 7 ]. The relationship between vitamin C and cardiovascular diseases in diabetes is not straightforward, a large study on women reported that supplement of more than 300 mg/day of vitamin C was positively associated with mortality outcomes in those with diabetes [ 8 ]. In contrast, vitamin C intake from food only showed no clear trend with mortality outcomes [ 8 ]. It appears that the effect of vitamin C is different whether the intake is from natural food or from supplements. It should be emphasized that lifestyle changes and a healthy diet are included in the prevention and/or treatment of atherosclerosis in patients with or without DM [ 9 ]. High intake of fresh fruits and vegetables, whole grains, and oil seeds and low intake of sodium are usually recommended [ 10 ]. Fruits intake is usually limited in quality and quantity in patients with diabetes for its impact on glycemia. However, recent studies seem to show that fresh fruits intake has no significant impact on glycemia [ 11 ] while has beneficial effect on cardiovascular risk [ 12 ]. Therefore, the aims of the present study were to estimate the prevalence of vitamin C deficit in ambulatory patients with type 2 diabetes, to study the relationship of vitamin C levels and cardiovascular diseases and to correlate the fresh fruits and vegetables consumption with vitamin C levels and the presence of cardiovascular diseases. In our study we carefully excluded patients who took vitamin supplements during the six months preceding the study in order to observe the relationship with exclusively diet related intake of vitamin C. MATERIALS AND METHODS In this study, 200 patients attending our diabetic clinic were recruited. Inclusion criteria were age between 18 and 80 years, both sexes and type 2 diabetes diagnosed at least 3 months before the enrollment; exclusion criteria were a history of pernicious anemia, autoimmune gastritis, pregnancy, vitamin supplementation within 6 months before the study. The study was approved by the local ethics committee (n°3853CESC), and informed consent was obtained from each participant. Patient under study during the programmed blood test for the medical control underwent a further blood test for the measurement of vitamin C. The quantitative analysis of vitamin C in human plasma is a critical issue since it is known that vitamin C concentration starts to decrease soon after blood withdrawal [ 13 ]. In fact, due to its very labile nature, in ex vivo conditions, acid ascorbic is progressively oxidized to dehydroascorbic acid which in turn is irreversibly hydrolyzed to the more stable metabolite 2,3-diketo-L-gulonic acid. In order to prevent such oxidation the following validated procedure was carried out [ 14 ]: Li-heparin tubes were filled up to 1/10th of their vacuum volume with a sterile saline solution containing 50 mM of 1,4-Dithioerythritol (DTE, Sigma-Aldrich®) reducing agent at 10× the selected final concentration. In order to preserve the residual vacuum, a sterile insulin syringe was used and the delivered volumes were checked gravimetrically. The procedure was performed in a sterile environment and the tubes thus prepared were stored at + 4°C until use for a maximum of 7 days. Finally, the vitamin C quantification in treated plasma samples, was carried out by reverse phase high performance liquid chromatography with UV detection (HPLC Prominance, Shimadzu,) using a CE-IVD validated kit from Chrimsystems (Munich, Germany). Vitamin C final concentrations were corrected for the plasma dilution factor. Duration of diabetes was computed from the date of diagnosis of diabetes. Body mass index (BMI) was calculated by dividing weight in kilograms by height in meters squared. A physician measured blood pressure with a mercury sphygmomanometer after patients had been seated quietly for at least 5 minutes. Patients were considered to have hypertension if their blood pressure was ≥ 140/90 mmHg or if they were taking any anti-hypertensive drugs. Information on smoking status and use of medications was obtained from all patients via interviews during medical examinations. Venous blood samples were drawn in the morning after an overnight fast. Serum creatinine (measured using a Jaffé rate-blanked and compensated assay) and other biochemical blood measurements were determined using standard laboratory procedures (DAX 96; Bayer Diagnostics, Milan, Italy). Low-density lipoprotein-cholesterol was calculated using the Friedewald’s equation. Hemoglobin A1c (HbA1c) was measured by an automated high-performance liquid chromatography analyzer (HA-8140; Menarini Diagnostics, Florence, Italy). The glomerular filtration rate (GFR) was estimated by the CKD Epidemiology Collaboration (CKD-EPI) equation [ 15 ]. Albuminuria was measured by an immuno-nephelometric method on a morning spot urine sample and expressed as the albumin-to-creatinine ratio. In all participants, the presence of microvascular diabetic complications was recorded. Nutritional Data All patients were required to compile a dedicated nutritional questionnaire to estimate the frequency of the consumption of fresh fruits and vegetables. Statistical Analysis Data were summarized as mean ± SD for continuous variables and absolute value or percentage for categorical variables. Differences in clinical/ biochemical characteristics were tested with the Student’s t-test for normally distributed variables and the Mann–Whitney test for non-normally distributed variables. ANOVA were used for variables with three or more categories. The χ2 test was used for categorical variables to study differences in proportions or percentages between the two groups. Three forced-entry logistic regression models were performed: an unadjusted model; a model adjusted for age and BMI; HbA1c, eGFRCKDEPI and sex. Covariates for these multivariate regression models were chosen as potential confounding based on their biological plausibility. A p value of less than 0.05 was considered statistically significant. RESULTS We have studied 200 ambulatory patients with type 2 diabetes, 12.2% of them had values of vitamin C compatible with a deficiency (vitamin C ≤ 20 µmol/l). In Table 1 are reported the main clinical characteristics of patients according to the status of vitamin C level. The eGFR was significantly lower in the vitamin C deficiency group. Even though men had lower levels of vitamin C (45.1 ± 17.8 µmol/l men vs 51.8 ± 20.0 µmol/l women, p = 0.017), the proportion of vitamin C deficiency was not different between men and women (p = 0.146, Χ 2 test). Patients with vitamin C deficiency had lower levels of total and HDL-cholesterol, whereas triglycerides were higher. The hypocholesterolemic treatment did not affect the vitamin C levels C (47.4 ± 18.0 µmol/l no treatment vs 47.4 ± 19.0 µmol/l treatment, p = 0.999) in spite of an expected significant reduction of LDL-cholesterol levels in the treated group (103.6 ± 28.8 mg/dl no treatment vs 64.0 ± 24.0 mg/dl treatment, p < 0.001). Also drugs for diabetes did not affect the vitamin C levels. Table 1 Clinical characteristic of ambulatory patients with type 2 diabetes in relation to c vitamin deficiency. Vitamin C, µmol/L Normal concentration Deficiency p Age, yr 66.8 ± 8.8 66.1 ± 9.9 .707 Duration of diabetes, yr 11.7 ± 8.2 14.7 ± 7.8 .093 BMI, Kg/m2 28.2 ± 4.6 27.7 ± 4.6 .627 Systolic blood pressure, mmHg 133.5 ± 18.0 139.3 ± 21.0 .287 Diastolic blood pressure, mmHg 80.2 ± 10.1 77.5 ± 14.1 .386 Glycated hemoglobin, mmol/mol Hb 52.7 ± 11.4 56.4 ± 11.4 .140 Total cholesterol, mg/dl 146.4 ± 35.1 129.4 ± 32.1 .029 HDL-cholesterol, mg/dl 50.5 ± 16.3 40.7 ± 7.7 < .001 LDL-cholestrol, mg/dl 72.0 ± 28.6 62.5 ± 29.1 .139 Triglycerides, mg/dl 120.1 ± 94.5 130.8 ± 39.7 .021° AST, U/L 24.4 ± 11.7 28.4 ± 19.0 .331 ACR, mg/gr 106.7 ± 345.46 55.3 ± 75.5 .065° EGFR, ml/min 1.73 m2 81.5 ± 19.6 70.2 ± 22.5 .010 ° Test Mann-Whitney, otherwise t-test. Data are presented as mean ± standard deviation. BMI, body mass index; HDL, high density lipoprotein; LDL, low density lipoprotein; AST, aspartate transaminase; ACR, albumin creatinin ratio; eGFR, estimated glomerular filtration rate. Figure 1 shows that vitamin C levels is progressively and significantly lower with the worsening of carotid artery stenosis. Vitamin C levels were significantly lower in the presence of ischemic heart disease (49.0 ± 17.2 µmol/l no vs 38.3 ± 19.6 µmol/l yes, p = 0.004), whereas in the presence of peripheral artery disease there was a tendency to lower levels of vitamin C (48.0 ± 18.3 µmol/l no vs 41.3 ± 22.7 µmol/l yes, p = 0.148). Smoking habit did not show significant differences in vitamin C levels (49.8 ± 20.0 µmol/l no smokers, 41.8 ± 15.0 µmol/l smokers and 47.5 ± 18.0 µmol/l ex-smokers, p = 0.111, Anova). Consumption of fresh fruits and vegetables was associated with a significantly higher levels of vitamin C (28.7 ± 14.8 µmol/l no consumers, 45.4 ± 17.9 µmol/l less than 2 days a week and 49.8 ± 19.2 µmol/l more than 2 days a week, p = 0.057, Anova). Consumption of fresh fruits and vegetables was associated with a tendency to have higher levels of HDL-cholesterol. In order to better evaluate the relation of vitamin C levels and atherosclerotic burden, we created a categorical variable with 0 equal to the absence and 1 equal to the presence of ischemic heart diseases or peripheral artery disease or cerebrovascular disease or previous carotid thromboarterectomy. The vitamin C levels were significantly lower in the group with atherosclerotic conditions: 40.5 ± 19.8 µmol/l atherosclerotic conditions vs 49.7 ± 17.9 µmol/l without atherosclerotic conditions, p = 0.003. Moreover, the consumption of fresh fruits and vegetables was lower in patients with atherosclerotic conditions (33% did not consume, 17,9% consume less than 2 days a week and 30,4% more than 2 days a week, Tau of Goodman and Kruskal p = 0.019 with consumption of fresh fruits as dependent variable) Finally, in order to investigate the independent role of vitamin C levels, we run multivariate logistic models (Table 2 ) with the burden of atherosclerosis as dependent variable. Vitamin C levels were inversely and significantly associated with the atherosclerotic burden in all models. Other significant covariates were eGFR with an inverse relation and sex with an increased risk of association with atherosclerotic burden in men. Table 2 Multivariate logistic models of the presence of atherosclerotic disease* as dependent variable in ambulatory patients with type 2 diabetes. variables 1 model 2 model 3 model OR (CI-95%) p OR (CI-95%) p OR (CI-95%) p Vitamin C, µmol/L 0.97 (0.95–0.99) .004 0.97 (0.95–0.99) .004 0.98 (0.96-1.00) .059 Age, yrs 1.04 (1.00-1.09) .051 1.01 (0.96–1.07) .617 BMI, kg/m2 0.99 (0.91–1.06) .735 0.98 (0.90–1.07) .611 eGFR, ml/min 0.98 (0.96-1.00) .032 HbA1c, mmol/mol 1.03 (1.00-1.06) .062 Sex, M 2.61 (1.11–6.13) .028 *Atherosclerotic diseases: 0 equal to the absence and 1 equal to the presence of ischemic heart diseases or peripheral artery disease or cerebrovascular disease or previous carotid thromboarterectomy. Legend to figure DISCUSSION The main results of the present study are that 12.2% of ambulatory patients with type 2 diabetes present a deficiency of vitamin C and patients with established cardiovascular diseases show a significant lower blood level of this vitamin. The latter finding was confirmed in the multivariate logistic analysis where vitamin C levels resulted an inverse significant predictor associated with cardiovascular endpoints. The results of the study are reinforced by the fact that we took care in excluding patients who have assumed a vitamin C supplementation in the six months before the study. According to our study, a lower concentration of vitamin C was reported in type 2 diabetes and pre-diabetes conditions (16). Previous studies both in diabetic and non-diabetic populations have found either a positive or a negative relation between vitamin C supplementation and cardiovascular risk (18–19). Of note is the finding that vitamin C supplementation was associated with an increased cardiovascular risk (8). Vitamin C acts as a potent antioxidant (20) by scavenging physiologically reactive oxygen, chlorine and nitrogen species, but in-vitro experiments have also shown that it may have prooxidant activity (21). Interestingly, a recent study showed a different behavior on oxidation of vitamin C, C-vitamers, and other common ascorbic acid derivatives used as supplements (22). Therefore, the beneficial effect of vitamin C may be different, and sometime opposite, whether the intake is from natural sources or from supplements. We found that vitamin C levels increased progressively with the consumption of fresh fruits and vegetables, but consumption of these aliments and consequently the blood vitamin C levels were lower especially in our diabetic patients with cardiovascular complications. Of interest, also a recent study reported an inadequate intake of fresh fruits in diabetes (23). Then, considering the results of studies that suggest that vitamin C supplementation may have no protective effects on cardiovascular outcomes and the results of our and other studies (24,25), we would like to suggest that the consumption of fresh fruits and vegetables should be preferred than the vitamin C supplementation in patients with type 2 diabetes. Therefore, we found a clear association between low levels of vitamin C and carotid stenosis and heart ischemic diseases. Notably, we observed an inverse relation between vitamin C levels with the progressive percentage of the carotid artery stenosis. The low levels of vitamin C may be linked to cardiovascular diseases throughout endothelial dysfunction caused by an increase production of ROS (26). Nevertheless, supplementation with vitamin C seems not to be effective in all subjects to lower the ROS concentrations (27,28), suggesting again a difference between natural vitamin C acquired by the natural foods or by supplements. In this regard, the results of our study may have clinical implication as we reported an increased level of vitamin C in patients who consumed more fresh fruits and vegetables. Of interest, it was estimated that in the general population approximately either 5 or 8 million premature deaths may have been attributable to a fruit and vegetable intake of less than 500 g/d and 800 g/d, respectively (29). Thus, following the results of our study we believe that the consumption of fresh fruits and vegetables in patients with type 2 diabetes and cardiovascular should be encourage and regularly assessed in order to maintain an adequate intake. Important weaknesses of our study are the absence of a control group, the normal range of vitamin C levels was extracted from the literature and the study has a cross- sectional design limiting causal inferences. The strengths of the study are the number of participants, the care to exclude patients who took vitamin supplements, the precise laboratory method to measure vitamin C and the completeness of the database. In conclusion, our study seems to suggest that vitamin C might have an inverse relation with cardiovascular diseases. The intake of vitamin C from fresh fruits and vegetables may have a protective role. Declarations Ethics approval and consent to participate : The study was approved by the local ethics committee (n°3853CESC), and informed consent was obtained from each participant. Consent for publication : all the authors agreed for publication Competing of interests The authors declare that they have no conflict of interest. Fund This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Author Contribution AT contributed to the preparation of data, NV contributed to the preparation of data, EP laboratory analyses of vitamins, MG laboratory analyses of vitamins, ED laboratory analyses of vitamins and critically reviewed the manuscript, GZ analysis of data and wrote the manuscript. Data availability: The data of this study are available from the corresponding author upon reasonable request. The data cannot be accessed publicly due to specific limitations that could compromise the confidentiality and privacy of the participants. References Wilde PE, Conrad Z, Rehm CD, Pomeranz JL, Penalvo JL, Cudhea F, Pearson-Stuttard J, O'Flaherty M, Micha R, Mozaffarian D. Reductions in national cardiometabolic mortality achievable by food price changes according to Supplemental Nutrition Assistance Program (SNAP) eligibility and participation. J Epidemiol Community Health. 2018;72:817–24. Micha R, Coates J, Leclercq C, Charrondiere UR, Mozaffarian D. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3955661","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":273375248,"identity":"4621aa3a-2c9e-455c-8aac-d63a60988242","order_by":0,"name":"Anna Toffalini","email":"","orcid":"","institution":"University and Hospital Trust of Verona","correspondingAuthor":false,"prefix":"","firstName":"Anna","middleName":"","lastName":"Toffalini","suffix":""},{"id":273375249,"identity":"fe6a9e94-98b6-452d-aae6-42bb83699a59","order_by":1,"name":"Nicolò Vigolo","email":"","orcid":"","institution":"University and Hospital Trust of Verona","correspondingAuthor":false,"prefix":"","firstName":"Nicolò","middleName":"","lastName":"Vigolo","suffix":""},{"id":273375250,"identity":"cd9af94a-93dc-4902-8b03-e5d5fcb05e4c","order_by":2,"name":"Elisa Paviati","email":"","orcid":"","institution":"University and Hospital Trust of Verona","correspondingAuthor":false,"prefix":"","firstName":"Elisa","middleName":"","lastName":"Paviati","suffix":""},{"id":273375251,"identity":"16f1ca59-aba6-4014-99ea-dc3bf385d9fe","order_by":3,"name":"Matteo Gelati","email":"","orcid":"","institution":"University and Hospital Trust of Verona","correspondingAuthor":false,"prefix":"","firstName":"Matteo","middleName":"","lastName":"Gelati","suffix":""},{"id":273375252,"identity":"e9b164f3-eaf2-42b7-b68d-601f6165fb6a","order_by":4,"name":"Elisa Danese","email":"","orcid":"","institution":"University and Hospital Trust of Verona","correspondingAuthor":false,"prefix":"","firstName":"Elisa","middleName":"","lastName":"Danese","suffix":""},{"id":273375253,"identity":"e4227b24-6b34-4648-88af-8a141959af90","order_by":5,"name":"Giacomo Zoppini","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYDACZmROAoOEHAMDYwOQKUG8FmOYFjx60EBiA5SBU4u8O/PDDx9zbBjk23uPPXi4wyJ9w+3mNukKBos6XFoMD7MZS87clsbA2HMu3SDxjETuhjsH2yTP4HGYYTODGTPvtsMMzBI5ZhKJbUAtNxKbDRvwamH/BtbCBtWSbkBIizwzD8QWHqiWBKCWxof4tBgw8xSD/MIjwQPyS5uE4UywFgMJyQZctvQf3/jh4zYbOVCIPfzZVifPdyP9wcGGijp+nLYcgNA8QMSGLI5LA9AWhPUoWkbBKBgFo2AUIAAAZJRNBx23M4kAAAAASUVORK5CYII=","orcid":"","institution":"University and Hospital Trust of Verona","correspondingAuthor":true,"prefix":"","firstName":"Giacomo","middleName":"","lastName":"Zoppini","suffix":""}],"badges":[],"createdAt":"2024-02-14 09:01:52","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3955661/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3955661/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":51332816,"identity":"7ed7df56-3f7b-4f4a-b787-0cfe033c8660","added_by":"auto","created_at":"2024-02-19 18:00:55","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":41185,"visible":true,"origin":"","legend":"\u003cp\u003eThe figure shows mean values ± SD of vitamin C levels in the categories of carotid artery stenosis. Comparisons were carried out with ANOVA test.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3955661/v1/bf8b5f39d477743b1d66be78.png"},{"id":54328782,"identity":"80debc29-37f1-4f63-a6d2-1308fe501338","added_by":"auto","created_at":"2024-04-09 00:22:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":341237,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3955661/v1/3d560949-4da4-498f-984d-316d9ce6c3cf.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Association of low concentration of vitamin C and low fresh fruits and vegetables consumption with cardiovascular diseases in type 2 diabetes. Running title: vitaminC and cardiovascular diseases in type 2 diabetes","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eIt has been reported that nutrition and diet may account for approximately 45% of all adult cardiometabolic deaths in the United States [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Micronutrients are important components of a healthy diet [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], among these vitamin C is an essential required component [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Vitamin C is a fundamental antioxidant that plays roles both as co-factor for many important metabolic processes and a non-enzymatic quencher for free radicals otherwise capable of modifying cellular macromolecules [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePatients with type 2 diabetes are exposed to oxidative stress as a consequence of an increase in ROS production and lipid peroxidation [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Oxidative stress is supposed to play a physiopathological role in causing cardiovascular diseases, that are the main cause of morbidity and mortality in type 2 diabetes [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe relationship between vitamin C and cardiovascular diseases in diabetes is not straightforward, a large study on women reported that supplement of more than 300 mg/day of vitamin C was positively associated with mortality outcomes in those with diabetes [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In contrast, vitamin C intake from food only showed no clear trend with mortality outcomes [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. It appears that the effect of vitamin C is different whether the intake is from natural food or from supplements.\u003c/p\u003e \u003cp\u003eIt should be emphasized that lifestyle changes and a healthy diet are included in the prevention and/or treatment of atherosclerosis in patients with or without DM [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. High intake of fresh fruits and vegetables, whole grains, and oil seeds and low intake of sodium are usually recommended [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Fruits intake is usually limited in quality and quantity in patients with diabetes for its impact on glycemia. However, recent studies seem to show that fresh fruits intake has no significant impact on glycemia [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] while has beneficial effect on cardiovascular risk [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTherefore, the aims of the present study were to estimate the prevalence of vitamin C deficit in ambulatory patients with type 2 diabetes, to study the relationship of vitamin C levels and cardiovascular diseases and to correlate the fresh fruits and vegetables consumption with vitamin C levels and the presence of cardiovascular diseases. In our study we carefully excluded patients who took vitamin supplements during the six months preceding the study in order to observe the relationship with exclusively diet related intake of vitamin C.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003eIn this study, 200 patients attending our diabetic clinic were recruited. Inclusion criteria were age between 18 and 80 years, both sexes and type 2 diabetes diagnosed at least 3 months before the enrollment; exclusion criteria were a history of pernicious anemia, autoimmune gastritis, pregnancy, vitamin supplementation within 6 months before the study.\u003c/p\u003e \u003cp\u003e The study was approved by the local ethics committee (n\u0026deg;3853CESC), and informed consent was obtained from each participant.\u003c/p\u003e \u003cp\u003ePatient under study during the programmed blood test for the medical control underwent a further blood test for the measurement of vitamin C. The quantitative analysis of vitamin C in human plasma is a critical issue since it is known that vitamin C concentration starts to decrease soon after blood withdrawal [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In fact, due to its very labile nature, in ex vivo conditions, acid ascorbic is progressively oxidized to dehydroascorbic acid which in turn is irreversibly hydrolyzed to the more stable metabolite 2,3-diketo-L-gulonic acid. In order to prevent such oxidation the following validated procedure was carried out [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]: Li-heparin tubes were filled up to 1/10th of their vacuum volume with a sterile saline solution containing 50 mM of 1,4-Dithioerythritol (DTE, Sigma-Aldrich\u0026reg;) reducing agent at 10\u0026times; the selected final concentration. In order to preserve the residual vacuum, a sterile insulin syringe was used and the delivered volumes were checked gravimetrically. The procedure was performed in a sterile environment and the tubes thus prepared were stored at +\u0026thinsp;4\u0026deg;C until use for a maximum of 7 days. Finally, the vitamin C quantification in treated plasma samples, was carried out by reverse phase high performance liquid chromatography with UV detection (HPLC Prominance, Shimadzu,) using a CE-IVD validated kit from Chrimsystems (Munich, Germany). Vitamin C final concentrations were corrected for the plasma dilution factor.\u003c/p\u003e \u003cp\u003eDuration of diabetes was computed from the date of diagnosis of diabetes. Body mass index (BMI) was calculated by dividing weight in kilograms by height in meters squared. A physician measured blood pressure with a mercury sphygmomanometer after patients had been seated quietly for at least 5 minutes. Patients were considered to have hypertension if their blood pressure was \u0026ge;\u0026thinsp;140/90 mmHg or if they were taking any anti-hypertensive drugs. Information on smoking status and use of medications was obtained from all patients via interviews during medical examinations. Venous blood samples were drawn in the morning after an overnight fast. Serum creatinine (measured using a Jaff\u0026eacute; rate-blanked and compensated assay) and other biochemical blood measurements were determined using standard laboratory procedures (DAX 96; Bayer Diagnostics, Milan, Italy). Low-density lipoprotein-cholesterol was calculated using the Friedewald\u0026rsquo;s equation. Hemoglobin A1c (HbA1c) was measured by an automated high-performance liquid chromatography analyzer (HA-8140; Menarini Diagnostics, Florence, Italy). The glomerular filtration rate (GFR) was estimated by the CKD Epidemiology Collaboration (CKD-EPI) equation [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Albuminuria was measured by an immuno-nephelometric method on a morning spot urine sample and expressed as the albumin-to-creatinine ratio. In all participants, the presence of microvascular diabetic complications was recorded.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eNutritional Data\u003c/h2\u003e \u003cp\u003eAll patients were required to compile a dedicated nutritional questionnaire to estimate the frequency of the consumption of fresh fruits and vegetables.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eData were summarized as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD for continuous variables and absolute value or percentage for categorical variables. Differences in clinical/ biochemical characteristics were tested with the Student\u0026rsquo;s t-test for normally distributed variables and the Mann\u0026ndash;Whitney test for non-normally distributed variables. ANOVA were used for variables with three or more categories. The χ2 test was used for categorical variables to study differences in proportions or percentages between the two groups. Three forced-entry logistic regression models were performed: an unadjusted model; a model adjusted for age and BMI; HbA1c, eGFRCKDEPI and sex. Covariates for these multivariate regression models were chosen as potential confounding based on their biological plausibility. A p value of less than 0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eWe have studied 200 ambulatory patients with type 2 diabetes, 12.2% of them had values of vitamin C compatible with a deficiency (vitamin C\u0026thinsp;\u0026le;\u0026thinsp;20 \u0026micro;mol/l). In Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e are reported the main clinical characteristics of patients according to the status of vitamin C level. The eGFR was significantly lower in the vitamin C deficiency group. Even though men had lower levels of vitamin C (45.1\u0026thinsp;\u0026plusmn;\u0026thinsp;17.8 \u0026micro;mol/l men vs 51.8\u0026thinsp;\u0026plusmn;\u0026thinsp;20.0 \u0026micro;mol/l women, p\u0026thinsp;=\u0026thinsp;0.017), the proportion of vitamin C deficiency was not different between men and women (p\u0026thinsp;=\u0026thinsp;0.146, Χ\u003csup\u003e2\u003c/sup\u003e test). Patients with vitamin C deficiency had lower levels of total and HDL-cholesterol, whereas triglycerides were higher. The hypocholesterolemic treatment did not affect the vitamin C levels C (47.4\u0026thinsp;\u0026plusmn;\u0026thinsp;18.0 \u0026micro;mol/l no treatment vs 47.4\u0026thinsp;\u0026plusmn;\u0026thinsp;19.0 \u0026micro;mol/l treatment, p\u0026thinsp;=\u0026thinsp;0.999) in spite of an expected significant reduction of LDL-cholesterol levels in the treated group (103.6\u0026thinsp;\u0026plusmn;\u0026thinsp;28.8 mg/dl no treatment vs 64.0\u0026thinsp;\u0026plusmn;\u0026thinsp;24.0 mg/dl treatment, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Also drugs for diabetes did not affect the vitamin C levels.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical characteristic of ambulatory patients with type 2 diabetes in relation to c vitamin deficiency.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin C, \u0026micro;mol/L\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNormal concentration\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDeficiency\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, yr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e66.8\u0026thinsp;\u0026plusmn;\u0026thinsp;8.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e66.1\u0026thinsp;\u0026plusmn;\u0026thinsp;9.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.707\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDuration of diabetes, yr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e11.7\u0026thinsp;\u0026plusmn;\u0026thinsp;8.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e14.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.093\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI, Kg/m2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e28.2\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e27.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.627\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSystolic blood pressure, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e133.5\u0026thinsp;\u0026plusmn;\u0026thinsp;18.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e139.3\u0026thinsp;\u0026plusmn;\u0026thinsp;21.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.287\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiastolic blood pressure, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e80.2\u0026thinsp;\u0026plusmn;\u0026thinsp;10.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e77.5\u0026thinsp;\u0026plusmn;\u0026thinsp;14.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.386\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGlycated hemoglobin, mmol/mol Hb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e52.7\u0026thinsp;\u0026plusmn;\u0026thinsp;11.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e56.4\u0026thinsp;\u0026plusmn;\u0026thinsp;11.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.140\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal cholesterol, mg/dl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e146.4\u0026thinsp;\u0026plusmn;\u0026thinsp;35.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e129.4\u0026thinsp;\u0026plusmn;\u0026thinsp;32.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.029\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHDL-cholesterol, mg/dl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e50.5\u0026thinsp;\u0026plusmn;\u0026thinsp;16.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e40.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLDL-cholestrol, mg/dl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e72.0\u0026thinsp;\u0026plusmn;\u0026thinsp;28.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e62.5\u0026thinsp;\u0026plusmn;\u0026thinsp;29.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.139\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTriglycerides, mg/dl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e120.1\u0026thinsp;\u0026plusmn;\u0026thinsp;94.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e130.8\u0026thinsp;\u0026plusmn;\u0026thinsp;39.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.021\u0026deg;\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAST, U/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e24.4\u0026thinsp;\u0026plusmn;\u0026thinsp;11.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e28.4\u0026thinsp;\u0026plusmn;\u0026thinsp;19.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.331\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eACR, mg/gr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e106.7\u0026thinsp;\u0026plusmn;\u0026thinsp;345.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e55.3\u0026thinsp;\u0026plusmn;\u0026thinsp;75.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.065\u0026deg;\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEGFR, ml/min 1.73 m2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e81.5\u0026thinsp;\u0026plusmn;\u0026thinsp;19.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e70.2\u0026thinsp;\u0026plusmn;\u0026thinsp;22.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.010\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u0026deg; Test Mann-Whitney, otherwise t-test. Data are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation. BMI, body mass index; HDL, high density lipoprotein; LDL, low density lipoprotein; AST, aspartate transaminase; ACR, albumin creatinin ratio; eGFR, estimated glomerular filtration rate.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows that vitamin C levels is progressively and significantly lower with the worsening of carotid artery stenosis. Vitamin C levels were significantly lower in the presence of ischemic heart disease (49.0\u0026thinsp;\u0026plusmn;\u0026thinsp;17.2 \u0026micro;mol/l no vs 38.3\u0026thinsp;\u0026plusmn;\u0026thinsp;19.6 \u0026micro;mol/l yes, p\u0026thinsp;=\u0026thinsp;0.004), whereas in the presence of peripheral artery disease there was a tendency to lower levels of vitamin C (48.0\u0026thinsp;\u0026plusmn;\u0026thinsp;18.3 \u0026micro;mol/l no vs 41.3\u0026thinsp;\u0026plusmn;\u0026thinsp;22.7 \u0026micro;mol/l yes, p\u0026thinsp;=\u0026thinsp;0.148). Smoking habit did not show significant differences in vitamin C levels (49.8\u0026thinsp;\u0026plusmn;\u0026thinsp;20.0 \u0026micro;mol/l no smokers, 41.8\u0026thinsp;\u0026plusmn;\u0026thinsp;15.0 \u0026micro;mol/l smokers and 47.5\u0026thinsp;\u0026plusmn;\u0026thinsp;18.0 \u0026micro;mol/l ex-smokers, p\u0026thinsp;=\u0026thinsp;0.111, Anova).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eConsumption of fresh fruits and vegetables was associated with a significantly higher levels of vitamin C (28.7\u0026thinsp;\u0026plusmn;\u0026thinsp;14.8 \u0026micro;mol/l no consumers, 45.4\u0026thinsp;\u0026plusmn;\u0026thinsp;17.9 \u0026micro;mol/l less than 2 days a week and 49.8\u0026thinsp;\u0026plusmn;\u0026thinsp;19.2 \u0026micro;mol/l more than 2 days a week, p\u0026thinsp;=\u0026thinsp;0.057, Anova). Consumption of fresh fruits and vegetables was associated with a tendency to have higher levels of HDL-cholesterol.\u003c/p\u003e \u003cp\u003eIn order to better evaluate the relation of vitamin C levels and atherosclerotic burden, we created a categorical variable with 0 equal to the absence and 1 equal to the presence of ischemic heart diseases or peripheral artery disease or cerebrovascular disease or previous carotid thromboarterectomy. The vitamin C levels were significantly lower in the group with atherosclerotic conditions: 40.5\u0026thinsp;\u0026plusmn;\u0026thinsp;19.8 \u0026micro;mol/l atherosclerotic conditions vs 49.7\u0026thinsp;\u0026plusmn;\u0026thinsp;17.9 \u0026micro;mol/l without atherosclerotic conditions, p\u0026thinsp;=\u0026thinsp;0.003. Moreover, the consumption of fresh fruits and vegetables was lower in patients with atherosclerotic conditions (33% did not consume, 17,9% consume less than 2 days a week and 30,4% more than 2 days a week, Tau of Goodman and Kruskal p\u0026thinsp;=\u0026thinsp;0.019 with consumption of fresh fruits as dependent variable)\u003c/p\u003e \u003cp\u003eFinally, in order to investigate the independent role of vitamin C levels, we run multivariate logistic models (Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) with the burden of atherosclerosis as dependent variable. Vitamin C levels were inversely and significantly associated with the atherosclerotic burden in all models. Other significant covariates were eGFR with an inverse relation and sex with an increased risk of association with atherosclerotic burden in men.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariate logistic models of the presence of atherosclerotic disease* as dependent variable in ambulatory patients with type 2 diabetes.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003evariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e1 model\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e2 model\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003e3 model\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR (CI-95%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (CI-95%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOR (CI-95%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin C, \u0026micro;mol/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.97 (0.95\u0026ndash;0.99)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.97 (0.95\u0026ndash;0.99)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.98 (0.96-1.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e.059\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, yrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.04 (1.00-1.09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.051\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.01 (0.96\u0026ndash;1.07)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e.617\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI, kg/m2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.99 (0.91\u0026ndash;1.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.735\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.98 (0.90\u0026ndash;1.07)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e.611\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eeGFR, ml/min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.98 (0.96-1.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e.032\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHbA1c, mmol/mol\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.03 (1.00-1.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e.062\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex, M\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.61 (1.11\u0026ndash;6.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e.028\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e*Atherosclerotic diseases: 0 equal to the absence and 1 equal to the presence of ischemic heart diseases or peripheral artery disease or cerebrovascular disease or previous carotid thromboarterectomy.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003cb\u003eLegend to figure\u003c/b\u003e\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe main results of the present study are that 12.2% of ambulatory patients with type 2 diabetes present a deficiency of vitamin C and patients with established cardiovascular diseases show a significant lower blood level of this vitamin. The latter finding was confirmed in the multivariate logistic analysis where vitamin C levels resulted an inverse significant predictor associated with cardiovascular endpoints. The results of the study are reinforced by the fact that we took care in excluding patients who have assumed a vitamin C supplementation in the six months before the study.\u003c/p\u003e \u003cp\u003eAccording to our study, a lower concentration of vitamin C was reported in type 2 diabetes and pre-diabetes conditions (16).\u003c/p\u003e \u003cp\u003ePrevious studies both in diabetic and non-diabetic populations have found either a positive or a negative relation between vitamin C supplementation and cardiovascular risk (18\u0026ndash;19). Of note is the finding that vitamin C supplementation was associated with an increased cardiovascular risk (8). Vitamin C acts as a potent antioxidant (20) by scavenging physiologically reactive oxygen, chlorine and nitrogen species, but in-vitro experiments have also shown that it may have prooxidant activity (21). Interestingly, a recent study showed a different behavior on oxidation of vitamin C, C-vitamers, and other common ascorbic acid derivatives used as supplements (22). Therefore, the beneficial effect of vitamin C may be different, and sometime opposite, whether the intake is from natural sources or from supplements.\u003c/p\u003e \u003cp\u003eWe found that vitamin C levels increased progressively with the consumption of fresh fruits and vegetables, but consumption of these aliments and consequently the blood vitamin C levels were lower especially in our diabetic patients with cardiovascular complications. Of interest, also a recent study reported an inadequate intake of fresh fruits in diabetes (23). Then, considering the results of studies that suggest that vitamin C supplementation may have no protective effects on cardiovascular outcomes and the results of our and other studies (24,25), we would like to suggest that the consumption of fresh fruits and vegetables should be preferred than the vitamin C supplementation in patients with type 2 diabetes.\u003c/p\u003e \u003cp\u003eTherefore, we found a clear association between low levels of vitamin C and carotid stenosis and heart ischemic diseases. Notably, we observed an inverse relation between vitamin C levels with the progressive percentage of the carotid artery stenosis.\u003c/p\u003e \u003cp\u003eThe low levels of vitamin C may be linked to cardiovascular diseases throughout endothelial dysfunction caused by an increase production of ROS (26). Nevertheless, supplementation with vitamin C seems not to be effective in all subjects to lower the ROS concentrations (27,28), suggesting again a difference between natural vitamin C acquired by the natural foods or by supplements.\u003c/p\u003e \u003cp\u003eIn this regard, the results of our study may have clinical implication as we reported an increased level of vitamin C in patients who consumed more fresh fruits and vegetables. Of interest, it was estimated that in the general population approximately either 5 or 8\u0026nbsp;million premature deaths may have been attributable to a fruit and vegetable intake of less than 500 g/d and 800 g/d, respectively (29). Thus, following the results of our study we believe that the consumption of fresh fruits and vegetables in patients with type 2 diabetes and cardiovascular should be encourage and regularly assessed in order to maintain an adequate intake.\u003c/p\u003e \u003cp\u003eImportant weaknesses of our study are the absence of a control group, the normal range of vitamin C levels was extracted from the literature and the study has a cross- sectional design limiting causal inferences. The strengths of the study are the number of participants, the care to exclude patients who took vitamin supplements, the precise laboratory method to measure vitamin C and the completeness of the database.\u003c/p\u003e \u003cp\u003eIn conclusion, our study seems to suggest that vitamin C might have an inverse relation with cardiovascular diseases. The intake of vitamin C from fresh fruits and vegetables may have a protective role.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003e \u003cb\u003eEthics approval and consent to participate\u003c/b\u003e:\u003c/strong\u003e \u003cp\u003eThe study was approved by the local ethics committee (n\u0026deg;3853CESC), and informed consent was obtained from each participant.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003e \u003cb\u003eConsent for publication\u003c/b\u003e:\u003c/strong\u003e \u003cp\u003e all the authors agreed for publication\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting of interests\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eFund\u003c/strong\u003e \u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAT contributed to the preparation of data, NV contributed to the preparation of data, EP laboratory analyses of vitamins, MG laboratory analyses of vitamins, ED laboratory analyses of vitamins and critically reviewed the manuscript, GZ analysis of data and wrote the manuscript.\u003c/p\u003e\u003ch2\u003eData availability:\u003c/h2\u003e \u003cp\u003eThe data of this study are available from the corresponding author upon reasonable request. The data cannot be accessed publicly due to specific limitations that could compromise the confidentiality and privacy of the participants.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWilde PE, Conrad Z, Rehm CD, Pomeranz JL, Penalvo JL, Cudhea F, Pearson-Stuttard J, O'Flaherty M, Micha R, Mozaffarian D. Reductions in national cardiometabolic mortality achievable by food price changes according to Supplemental Nutrition Assistance Program (SNAP) eligibility and participation. J Epidemiol Community Health. 2018;72:817\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMicha R, Coates J, Leclercq C, Charrondiere UR, Mozaffarian D. Global Dietary Surveillance: data gaps and challenges. Food Nutr Bull. 2018;39:175\u0026ndash;205.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalters GWM, Redman E, Gulsin GS, Henson J, Argyridou S, Yates T, Davies MJ, Parke K, McCann GP, Brady EM. (20121). 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Inadequate Vitamin C Status in Prediabetes and Type 2 Diabetes Mellitus: Associations with Glycaemic Control, Obesity, and Smoking. Nutrients. 2017;9:997\u0026ndash;1004.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOsganian SK, Stampfer MJ, Rimm E, Spiegelman D, Hu FB, Manson JE, Willett WC. Vitamin C and risk of coronary heart disease in women. J Am Coll Cardiol. 2003;42:246\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShah AK, Dhalla NS. Effectiveness of Some Vitamins in the Prevention of Cardiovascular Disease: A Narrative Review. Front Physiol. 2021;12:729255\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorelli MB, Gambardella J, Castellanos V, Trimarco V, Santulli G. Vitamin C and Cardiovascular Disease: An Update. Antioxid (Basel). 2020;9:1227\u0026ndash;37.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSantos KLB, Bragan\u0026ccedil;a VAN, Pacheco LV, Ota SSB, Aguiar CPO, Borges RS. Essential features for antioxidant capacity of ascorbic acid (vitamin C). J Mol Model. 2021;28:1\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePoljsak B, Raspor P. The antioxidant and pro-oxidant activity of vitamin C and trolox in vitro: a comparative study. J Appl Toxicol. 2008;28:183\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJakubek P, Suliborska K, Kuczyńska M, Asaduzzaman M, Parchem K, Koss-Mikołajczyk I, Kusznierewicz B, Chrzanowski W, Namieśnik J, Bartoszek A. The comparison of antioxidant properties and nutrigenomic redox-related activities of vitamin C, C-vitamers, and other common ascorbic acid derivatives. Free Radic Biol Med. 2023;209:239\u0026ndash;51.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun H, Weaver CM. Trends in Diet Quality and Increasing Inadequacies of Micronutrients Vitamin C, Vitamin B12, Iron and Potassium in US Type 2 Diabetic Adults. Nutrients. 2023;15:1980\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLamb MJ, Griffin SJ, Sharp SJ, Cooper AJ. Fruit and vegetable intake and cardiovascular risk factors in people with newly diagnosed type 2 diabetes. Eur J Clin Nutr. 2017;71:115\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen Y, Su J, Qin Y, Luo P, Shen C, Pan E, Lu Y, Miao D, Zhang N, Zhou J, Yu X, Wu M. Fresh fruit consumption, physical activity, and five-year risk of mortality among patients with type 2 diabetes: A prospective follow-up study. Nutr Metab Cardiovasc Dis. 2022;32:878\u0026ndash;88.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQin X, Qin L, Luo J, Liu B, Zhao J, Li H, Wei Y. Correlation analysis between 25-hydroxyvitamin D3, vitamin B12 and vitamin C and endothelial function of patients with CHD. Exp Ther Med. 2019;17:418\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePodmore ID, Griffiths HR, Herbert KE, Mistry N, Mistry P, Lunec J. Vitamin C exhibits pro-oxidant properties. Nature. 1998;392:559.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu YJ, Tappia PS, Neki NS, Dhalla NS. Prevention of diabetes-induced cardiovascular complications upon treatment with antioxidants. Heart Fail Rev. 2014;19:113\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAune D, Giovannucci E, Boffetta P, Fadnes LT, Keum N, Norat T, Greenwood DC, Riboli E, Vatten LJ, Tonstad S. 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Int J Epidemiol. 2017;46:1029\u0026ndash;56.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"diabetes, antioxidant, vitamin C, fresh fruit, diet","lastPublishedDoi":"10.21203/rs.3.rs-3955661/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3955661/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eVitamin C is a fundamental antioxidant that plays roles in important metabolic processes. Patients with type 2 diabetes are exposed to oxidative stress as a consequence of an increase in ROS production. The aims of the present study were to estimate the prevalence of vitamin C deficiency in ambulatory patients with type 2 diabetes, to study the relationship of vitamin C levels and cardiovascular diseases and to correlate the fresh fruits and vegetables consumption with vitamin C levels and the presence of cardiovascular diseases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn 200 ambulatory patients with type 2 diabetes, vitamin C levels, with HPLC, and consumption of fresh fruits and vegetables, with a dedicated questionnaire, were measured. All other laboratory variables were measured with standard methods. Association between vitamin C and cardiovascular diseases was assessed using multivariable logistic regression analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eVitamin C deficiency was found in 12.2 % of subjects. Vitamin C levels and consumption of fresh fruits and vegetables were lower in subjects with cardiovascular diseases. Fresh fruits and vegetables intake were associated with higher levels of vitamin C. In multivariable analysis, vitamin C was independently associated with cardiovascular diseases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn conclusion, our study seems to suggest that vitamin C might have an inverse relation with cardiovascular diseases. The intake of vitamin C from fresh fruits and vegetables may have a protective role.\u003c/p\u003e","manuscriptTitle":"Association of low concentration of vitamin C and low fresh fruits and vegetables consumption with cardiovascular diseases in type 2 diabetes. Running title: vitaminC and cardiovascular diseases in type 2 diabetes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-19 18:00:03","doi":"10.21203/rs.3.rs-3955661/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"25f5d168-5604-4c1d-b429-8f097c443051","owner":[],"postedDate":"February 19th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-04-09T00:14:30+00:00","versionOfRecord":[],"versionCreatedAt":"2024-02-19 18:00:03","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3955661","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3955661","identity":"rs-3955661","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}