If you are a woman over the age of 65 having trouble losing weight, you may want to get your vitamin D levels checked. At least that’s the conclusion of a new study featured in June 2012 in the Journal of Women’s Health.

Researchers from Kaiser Permanente Center for Health Research in Portland, Ore., evaluated vitamin D levels and weight in 4,600 women age 65 and older. They found that the women with below-normal levels of vitamin D gained about two pounds more than those with normal levels during the five-year study. 

While this may not seem significant, the researchers also noted that the women with below-normal levels also weighed more at the beginning of the study than the women with normal levels. Normal levels of vitamin D are 30 ng/ml or higher. 

The researchers point out that their study does not identify whether the low vitamin D levels caused the weight gain or merely reflected it. Researcher Erin LeBlanc, MD, says there are some theoretical ways that adequate vitamin D could contribute to normal weight. For instance, she says that fat cells have vitamin D receptors, and if they get enough vitamin D, the fat cells shrink. If there is not enough D, fat cells get bigger.  

In addition to weight loss, vitamin D deficiency has been linked to everything from cancer risk and heart disease to mental health issues such as depression. Research continues to expand in a variety of areas. 

In November 2010, the Institute of Medicine raised the recommended daily intake of vitamin D to 600 IU for people age 1 to 70 and 800 IU for people over age 70. Some experts feel even this new recommendation is too low.

Listen to a radio show exclusively about vitamin D featuring Wellness Times Editorial Advisor Gregory Plotnikoff, MD.