Background and aims: A negative association between vitamin D and obesity has been proposed in a number of studies. A possible impact of ethnicity on levels of vitamin D and obesity has also been discussed, but data are ambiguous. Our aim was to study the relationship between serum levels of 25-hydroxyvitamin D (25(OH) vitamin D) and measures of obesity in two ethnic cohorts having type 2 diabetes.
Methods: In the present study, sixty-one subjects recruited for the DIVINE study (Diabetes Intervention Trial with Vitamin D in Subjects of Sub-Indian and Nordic Ethnicity), were included. Waist and hip circumference was measured and BMI (Body Mass Index) was calculated to evaluate obesity. Body composition including regional distribution of fat, was depictured by bio-electrical impedance and DXA.
Results: Subjects, 60% males, 31,1% of South-Asian ethnicity, had a mean age of 55,5 years, a mean BMI of 31,8 kg/m2 and a median S-25(OH) vitamin D of 38,0 nmol/l. There were no correlations between S-25(OH) vitamin D and any measures of obesity in the total cohort. In South-Asians S-25(OH) vitamin D correlated negatively with waist-hip-ratio (WHR), r=0,547, p=0,016.
Conclusions: There were no associations between S-25(OH) vitamin D and measures of obesity in the total cohort. A significant negative correlation was found between S-25(OH) vitamin D and WHR in South-Asians. Further studies are warranted to explore the relationship between vitamin D and obesity, preferably in multi-ethnic populations as there might be ethnic differences.