Effects of Vitamin D Supplementation on Female Vitamin D Deficient Teenagers: A Randomized Clinical Trial

Background: Vitamin D deficiency is one of the most prevalent disorders worldwide. Considering the magnitude of growth in adolescence, the aim of this study was to ascertain the prevalence of vitamin D deficiency and discover the association between anthropometric indices and vitamin D levels and the effect of vitamin D treatment on anthropometric indices in adolescent girls. Method: we performed this randomized clinical trial study (approved by Iranian Registry of Clinical Trials with code of IRCT20200615047785N2) conducting 313 high school girl students in a random cluster sampling from Jahrom city schools. Blood samples were collected from participants to determine the serum level (OH) D25. We divided vitamin D deficient patients into two groups: control who received placebo (n=150) and intervention group (n=150) who were prescribed one tablet of 50,000 units of vitamin D per week for eight weeks. Anthropometric indices of participants were measured before and after the intervention. Datas were analyzed by SPSS software version 19. Results: : The prevalence of vitamin D deficiency was 95%. Body mass index had no significant difference before the intervention in both groups (P = 0.76). After intervention in the case group, body mass index increased significantly (P = 0.01), but there was no significant difference in the control group after treatment (P = 0.42). There was no significant difference in waist circumference, height and weight before and after the intervention in both groups (P > 0.05). There was also a weak but significant correlation between height, weight, and baseline 25OHD levels of participants. Conclusion: The results of this study showed that there is a reverse and significant relationship between height and weight index with 25OHD. Further monitoring and prolonged studies with extended follow ups might improve the anthropometric parameters after treatment.