| At The Endocrine Society's 91st Annual Meeting, held this month in Washington, D.C., University of Minnesota assistant professor of medicine Shalamar Sibley, MD, MPH reported that men and women with higher vitamin D levels experienced a greater amount of weight loss when dieting compared to those with lower levels. For their study, Dr Sibley and colleagues measured plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D (the precursor and hormonal forms of vitamin D) in 38 obese subjects prior to and following an 11 week diet plant that provided 750 calories less per day than the participants' estimated needs. Fat distribution and body composition were measured using dual-energy X-ray absorptiometry and computed tomography before and after the treatment period. The participants' vitamin D levels were found to be insufficient on average. The researchers observed a linear relationship between baseline vitamin D levels and weight loss, with close to an additional half pound of weight loss associated with each 1 nanogram per milliliter (ng/mL) increase in plasma 25-hydroxyvitamin D, as well as nearly one quarter pound loss with each nanogram increase in 1,25-dihydroxyvitamin D. Higher levels of both forms of the vitamin were associated with more abdominal fat loss, and neither form was associated with lean mass loss. "Plasma vitamin D predicts subsequent weight loss, suggesting a potential role for vitamin D in promotion of weight loss, perhaps through effects on adipose metabolism," the authors conclude in their abstract concerning the findings. "Vitamin D deficiency is associated with obesity, but it is not clear if inadequate vitamin D causes obesity or the other way around," Dr Sibley commented. "Our results suggest the possibility that the addition of vitamin D to a reduced-calorie diet will lead to better weight loss." "Our findings need to be followed up by the right kind of controlled clinical trial to determine if there is a role for vitamin D supplementation in helping people lose weight when they attempt to cut back on what they eat," she added. | 
