An eloquent study, published in Nutrition Journal, investigated the effects of 12 weeks Vitamin D supplementation on body composition indices in healthy and overweight or obese women. The term Vitamin D refers to a group of fat-soluble pro-hormones which play an important role in regulating bone health, immune function and muscle function. Growing evidence has also illustrated a link between low Vitamin D concentrations and components of body composition, most notably body fat mass. The fact that fat mass distribution (particularly visceral distribution) breeds a toxic milieu that can cause cardiovascular, endocrine and malignant disease states, coupled with the fact that the state of Vitamin D deficiency has been termed with an estimated one billion individuals suffering worldwide, inspired researchers at the Beheshti University of Medical Sciences to determine for themselves the role of Vitamin D in improving body composition indices.
The study was conducted in a double-blind (meaning neither the researchers nor participants were aware of which treatment was being given), randomised, placebo-controlled fashion. Seventy-seven participants were recruited and split into two groups: Vitamin D3 (25 μg per day as cholecalciferol) and placebo (25 μg per day as lactose) for twelve weeks. A number of measurements were obtained before and after the treatment period of which included: body weight, height, waist, hip, fat mass, 25(OH)D (the most accurate way to measure vitamin D status), iPTH and dietary intakes.
The findings revealed that Serum 25(OH)D levels increased by a staggering (and statistically significant!) 104% to 75 nmol/L (deemed sufficiency) in the Vitamin D3 group pre- to post-treatment, whereas no significant changes were observed in the control group. Interestingly, this translated into a significant reduction in body fat mass in the Vitamin D3 group when compared with control (see Figure below). Weight loss, waist circumference and hip circumference were relatively static between conditions, however there was a trend for Vitamin D3 supplementation to improve these parameters, for example: waist circumference decreased in the Vitamin D3 group, yet increased in the control group (-0.3 ± 4.3 cm vs. 0.4 ± 4.1 cm).
Concluding statement - The role of Vitamin D as an important mediator of health is becoming increasingly apparent and is particularly evident when looking at the Harvard Universities food pyramid (http://www.hsph.harvard.edu/nutritio...u-eat/pyramid/) where daily vitamin D supplementation is advised for most people. On this basis, if inadequacy is a possibility, then supplementation (in most cases) is advised. Initial data showing the role of Vitamin D supplementation in assisting with fat loss looks promising. It is postulated that Vitamin D achieves this through reducing the production and storage of fat while increasing its synthesis - controlled by hormones such as parathyroid and calcitrol, as well as calcium through which Vitamin D has a synergistic relationship with. Contemporary research also reveals that vitamin D receptor polymorphisms are associated with adiposity phenotypes. This remains a controversial and highly debated topic area within the scientific literature and much more research is required to substantiate the efficacy of Vitamin D’s ‘fat burning’ role.
Salehpour et al.: A 12-week double-blind randomized clinical trial of vitamin D3 supplementation on body fat mass in healthy overweight and obese women. Nutrition Journal 2012 11:78.