The association between the level of vitamin D3 and insulin resistance in the general adult population of the United States: A cross-sectional study based on the NHANES database

Background: Nowadays, the number of patients with type 2 diabetes is increasing yearly, the leading cause of which is insulin resistance. Therefore, it is imperative to investigate the causes of insulin resistance in the population. Understanding the mechanism of insulin resistance can effectively prevent and control the occurrence of type 2 diabetes. Few studies been conducted from the perspective of the general population previously, now, we used the NHANES public database to analyze the relationship between vitamin D3 and insulin resistance in the general population of the United States (≥18 years old), to provide clinical evidence and try to find a appropriate level of vitamin D3 in the general population. Methods: The Health Center conducted a survey from 2008 to 2018, covering five cycles with 49,696 participants who were eligible for the study. Multivariate logistic regression was used to analyze the relationship between vitamin D3 and insulin resistance, excluding other potential confounders, and a smooth curve fitting was drawn. Result: This study found a significant association between vitamin D3 and insulin resistance, with an odds ratio and 95%CI of 0.89 (0.83, 0.95). The association was most significant at BMI 24-28, with odds ratio and 95%CI of 0.80(0.69, 0.93). Conclusion: This study suggests that keeping vitamin D3 levels as high as possible in the general US population can effectively reduce the incidence of insulin resistance.