Relationship between Obesity and Serum 25-Hydroxyvitamin D Concentrations

ABSTRACT

BACKGROUND: Vitamin D has been known to play an important role in calcium homeostasis and bone metabolism. It has also been implicated in diabetes mellitus, cardiovascular disease, and immune diseases. Several cross-sectional studies conducted worldwide have found that vitamin D is negatively correlated with obesity. In Korea, however, the results of similar studies were found to be inconsistent.METHODS: The study consisted of 585 adults over 18 years of age, who visited a health promotion center at a university hospital from March, 2015 to February, 2016 and their serum vitamin D levels were recorded. They were divided into two groups according to their sex. The correlation coefficients were calculated using Pearson correlation analysis between obesity and vitamin D. Finally, subjects with vitamin D levels less than <20 ng/mL were classified as deficient. Bivariate logistic regression analysis was used to determine the odds ratio of vitamin D deficiency.RESULTS: We observed a significant negative correlation between obesity and vitamin D (P<0.05) among the women but not in the men. The following are the details of the findings: ≥25 in body mass index (model 3 adjusted odds ratio [OR], 4.11; 95% confidence interval [CI], 1.59–10.67), ≥85 cm in waist circumference (model 3 adjusted OR, 1.81; 95% CI, 1.02–4.01), ≥30% in body fat (model 3 adjusted OR, 2.29; 95% CI, 1.17–4.62).CONCLUSION: Based on the results of this study, we suggest that obesity and vitamin D are negatively correlated and that obesity in women predisposes them to vitamin D deficiency.