Effects of Vitamin D Supplementation on Healthy, Overweight, and Obese Adults: A Non-Blinded, Randomized Trial

Abstract

A growing body of literature recognizes the role of vitamin D deficiency in various health-related problems such as obesity, cardiovascular diseases, and dyslipidemia. Hence, we design a small non-blinded randomized clinical study to explore some of these effects. The primary outcome was to investigate whether supplementation with vitamin D could reduce body mass index (BMI), while the secondary outcome was to see its effects on blood pressure (BP), serum total cholesterol (TC), and HDL-cholesterol over 12 weeks period in overweight otherwise healthy individuals. Twenty-two subjects were randomized into two groups, group A was given vitamin D supplementation of 200 IU/day and group B was assigned to 2000 IU/day. A baseline assessment of body mass index (BMI), blood pressure (BP), serum total cholesterol (TC), and serum HDL-cholesterol was performed at baseline, 4, 8, and 12 weeks. Repeated measure ANOVA was used to determine the effect of supplements within subjects and between the groups of our study. The study was unable to demonstrate any statistically significant effects of these supplemental doses of vitamin D on both primary and secondary outcomes over the study period. The scope of this study was limited by a small sample size and a large randomized double-blinded clinical study could provide more definitive evidence.