Boosting Vitamin D May Not Protect Bones

High-dose vitamin D in postmenopausal women may not be beneficial

Low levels of vitamin D can be a problem for older women, but supplements may not be the answer.

A new study from the University of Wisconsin found that high doses of vitamin D may not improve bone density, muscle function or muscle mass in postmenopausal women.

"High-dose [vitamin D] therapy increased calcium absorption, but the effect was small and did not translate into beneficial effects on bone mineral density, muscle function, muscle mass, or falls," said lead study author Karen E. Hansen, MD, of the University of Wisconsin School of Medicine and Public Health, in a press release.

Adequate vitamin D intake is important for calcium absorption, which is needed to maintain healthy bones and teeth.

After menopause, many women are more susceptible to osteoporosis (a thinning of the bones.)

Low vitamin D levels are also linked to a greater risk of bone fractures in women after menopause.

Dr. Hansen and team looked at 230 postmenopausal women under the age of 75 who had low vitamin D levels. These women did not have risk factors for other kinds of bone complications.

The women were divided into three groups. One group was given a placebo, one group was given low-dose vitamin D and one group was given high-dose vitamin D.

Patients in the high-dose group achieved higher vitamin D blood levels.

However, Dr. Hansen and team found no benefits in terms of falls, bone density, muscle mass or function.

According to Dr. Hansen and team, these results may not apply to young women or women older than 75.

This study was published in the August issue of the journal JAMA Internal Medicine.

The National Institute on Aging and the US Office of Dietary Supplements funded this research. No conflicts of interest were disclosed.