It might sound strange, but taking higher doses of vitamin D or sitting in the sun may not always be the best way to boost your vitamin D levels.  For some people losing weight might do the trick.    

In fact, overweight or obese women who lose more than 15 percent of their body weight significantly increase their circulating levels of vitamin D.

Researchers at Fred Hutchinson Cancer Research Center followed 439 overweight-to-obese, sedentary, postmenopausal women, ages 50 to 75, for one year.  The women were randomly assigned to one of four groups: exercise only, diet only, exercise plus diet and no intervention.

Those who lost 5 percent to 10 percent of their body weight through diet and/or exercise saw a relatively small increase in blood levels of vitamin D (about 2.7 nanograms per milliliter, or ng/mL).  But women who lost more than 15 percent of their weight almost tripled their vitamin D levels (about 7.7 ng/mL).

How did this happen? The authors theorized that obese and overweight people have lower levels of vitamin D because the nutrient is stored in fat deposits. They believe that during weight loss vitamin D trapped in fat tissue is released into the blood and becomes available for use throughout the body.

In their paper published online in the American Journal of Clinical Nutrition, the researchers noted that vitamin D is generally lower in obese people.  The lead author suggested that low vitamin D levels could account, in part, for the link between obesity and diseases such as cancer, heart disease and diabetes.

The researchers were surprised at the effect of weight loss on blood vitamin D levels. They noted that the relationship between weight loss and blood vitamin D is not linear.  It goes up dramatically with more weight loss. 

They noted that weight loss of 5 percent to 10 percent is generally recommended to improve risk factors such as blood pressure, cholesterol and blood sugars.  But they believed their findings suggest that more weight loss might be necessary to meaningfully raise blood vitamin D levels.

According to the National Institutes of Health, vitamin D plays many important roles in the body. It promotes calcium absorption and is needed for bone growth and bone healing and helps protect older adults from osteoporosis.  It also influences cell growth, neuromuscular and immune function, and reduces inflammation.

To read more about vitamin D, its benefits and recommended amounts, click here:  Vitamin D: How Much and What Are Its Benefits?