Background: The aim of this study was to examine the association between dietary intakes of vitamin D and the metabolic syndrome (MetS) in Tehranian adults, Iran.
Methods: In this population-based prospective study, a sample of 2357 subjects, aged 20-74 years, who had completed a validated food frequency questionnaire, were studied. MetS was defined according to the modified guidelines of the National Cholesterol Education Program Adults Treatment Panel III.
Results: Median intakes of vitamin D were 1.5 and 1.6 µ g/day in men and women respectively. After adjustment for confounding factors, dietary vitamin D intake was inversely associated with fasting blood glucose (β = -0.085, p = 0.004) and waist circumference (β = -0.065, p = 0.035); these associations were attenuated following further adjustment for demographics, body mass index (BMI) and dietary factors ((β = -0.066, p = 0.030) and (β = -0.065, p = 0.044), respectively. An association was observed between incidence of MetS and vitamin D intake (p trend = 0.040), independent of age, gender, smoking, physical activity; this association remained following further adjustment for BMI (p for trend = 0.044) and dietary factors (p for trend = 0.051).
Conclusion: Our findings suggest a significant inverse association between dietary vitamin D intake, MetS, and some of its components after controlling for confounding factors.