Losing weight results in more vitamin D

SEATTLE, May 25 (UPI) -- Overweight or obese women lacking in vitamin D who lose about 15 percent of their weight experience increases in the sunlight vitamin, U.S. researchers say.

Lead author Caitlin Mason of the Fred Hutchinson Cancer Research Center in Seattle says the yearlong study involved 439 overweight-to-obese, sedentary, post-menopausal Seattle-area women, ages 50-75, who were randomly assigned to one of four groups -- exercise only, diet only, exercise plus diet and no intervention.

The study, published in the American Journal of Clinical Nutrition, found those who lost 5 percent to 10 percent of their body weight -- approximately 10 to 20 pounds for most of the women -- through diet and/or exercise saw a relatively small increase in blood levels of vitamin D. But women who lost more than 15 percent of their weight experienced a nearly three-fold increase in vitamin D -- independent of dietary intake of the nutrient.

"Since vitamin D is generally lower in persons with obesity, it is possible that low vitamin D could account, in part, for the link between obesity and diseases such as cancer, heart disease and diabetes," Mason says in a statement. "Determining whether weight loss helps change vitamin D status is important for understanding potential avenues for disease prevention."

Vitamin D promotes calcium absorption and is needed for bone growth and bone healing influences cell growth, neuromuscular and immune function and reduces inflammation, the National Institutes of Health says.