Association Between Serum Vitamin D Concentrations and Markers of Adiposity in Ethnically Diverse Population

Abstract Objectives Background: South Asian Indians (SAI) have a higher prevalence of both chronic diseases and vitamin D deficiency compared to Caucasians. Previous research shows that vitamin D status is a determinant of metabolic health. SAIs have higher total fat, lower lean mass, and higher visceral or truncal fat compared to Caucasians. These factors are all associated with chronic health conditions at a younger age than their Caucasian counterparts. Objective The study aimed to determine the association between body composition parameters and the biomarkers of vitamin D status and whether these relationships differed between Caucasian and SAI cohorts. Methods Healthy SAIs and Caucasian men, who were 22 to 60 years of age, were enrolled. Anthropometric and body composition measurements, serum levels of 25 Hydroxy-vitamin D (25OHD), Parathyroid Hormone, and Vitamin D Binding-Protein were obtained. Independent t-test and Mann-Whitney u test were used to report the differences between groups. Spearman correlation was used to identify the possible association. A P value of less than 0.05 was considered significant. Results 30 SAIs and 30 Caucasians completed the study. Both groups did not significantly differ in their age and BMI. The 25OHD levels were statistically different between Caucasians (31.24 ± 9.14 ng/mL) and SAIs (22.94 ± 7.19 ng/mL), (P < 0.01). The correlation analysis found that among Caucasians, percent of Fat Free Mass (FFM), android fat, gynoid fat, visceral adipose tissue (VAT) correlated negatively with 25OHD levels (P < 0.05). Among SAIs, % of FFM, Fat Mass, Lean mass correlated negatively with 25OHD levels (P < 0.05). Conclusions VAT showed a negative association with vitamin D status in Caucasians only. These findings may have important implications for development of metabolic diseases in young Caucasian vs a SAI population. Funding Sources Drexel CNHP Seed Grant to Dr. Sukumar