Vitamin D Intake and Status Are Associated with Lower Prevalence of Metabolic Syndrome in US Adults: National Health and Nutrition Examination Surveys 2003-2006

Background: Previous reports have shown that metabolic syndrome and some metabolic syndrome components are associated with serum 25-hydroxyvitamin D [25(OH) D]. Methods: Using the National Health and Nutrition Examination Surveys (NHANES), 2003-2006, we evaluated the associations of vitamin D intake (n = 3543) and vitamin D status [25(OH) D; n = 3529], with the prevalence of metabolic syndrome and its components in adults 20 years and older. Exclusion criteria included nonfasted subjects, those pregnant and/or lactating, and, for intake analyses, those with unreliable 24-h recall records. Subjects were separately classified into quartiles of vitamin D intake (both including and excluding supplements) and serum 25(OH) D. Logistic regression was used to determine odds ratios (OR) for metabolic syndrome after adjusting for multiple confounders. Results: Those in the highest quartile of serum 25(OH) D had 60% lower odds for metabolic syndrome as compared to those in the lowest quartile [OR = 0.40; 95% confidence interval (CI) 0.27, 0.59]. Elevated waist circumference (OR = 0.57; 95% CI 0.39, 0.84), low high-density lipoprotein cholesterol (HDL-C) (OR = 0.54; 95% CI 0.39, 0.75), and high homeostasis model assessment of insulin resistance (HOMA-IR) (OR = 0.40; 95% CI 0.29, 0.55) were the main components associated with serum 25(OH) D. Compared with the lowest vitamin D intake quartile (excluding supplements), those in the highest intake quartile had 28% lower odds for metabolic syndrome (OR = 0.72; 95% CI 0.58, 0.90). No components of metabolic syndrome were significantly associated with dietary intake of vitamin D with supplements included or excluded. Conclusions: We conclude that higher 25(OH) D, and, to a lesser degree, greater dietary vitamin D intake, are associated with reduced prevalence of metabolic syndrome.