Vitamin D intake and status are associated with lower prevalence of metabolic syndrome in U.S. 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.