Vitamin D Supplementation Can Prevent Fractures

Category: Aging , Conditions of the Bone , Dietary Supplements

A recent study published in the Journal of the American Medical Association (May 11, 2005;293(18):2257-2264) analyzed randomized trials using Vitamin D and concluded that, in sufficient doses, this nutrient can be effective in preventing hip and nonvertebral fractures.

Researchers conducted a systematic review of English and non-English articles using MEDLINE, the Cochrane Controlled Trials Register (1960-2005), and EMBASE (1991-2005), as well as searching reference lists and abstracts presented at the American Society for Bone and Mineral Research from 1995 to 2004. A meta-analysis of only randomized controlled trials was performed using only trials with oral Vitamin D supplementation and a minimum follow-up of 1 year and more than a total of 1 fracture in each trial. The mean age of the subjects had to be above 60 years and the primary or secondary outcome of the trials was required to be hip or nonvertebral fractures.

In the primary analysis, 7 randomized controlled trials of subjects with a mean age of 79 years were reviewed. Two dosage levels of Vitamin D were separated to provide more homogeneous data. When the dosage level was between 700-800 IU per day of vitamin D, the risk of hip fracture was reduced by 26% compared to calcium or placebo. A dosage level of 400 IU daily had no effect on reducing hip fracture. For any nonvertebral fracture, the meta-analysis revealed a 23% reduction in fracture using a dose of 700-800 IU per day of vitamin D compared to calcium or placebo. Again, the lower dose of 400 IU daily had no significant effect on incidence of nonvertebral fractures.

The authors of the study concluded that "oral vitamin D supplementation in the range of 700 to 800 IU/d should reduce the risk of hip or any nonvertebral fracture by approximately 25%." They also state that "Vitamin D appears to have a beneficial effect on muscle strength and balance mediated through highly specific receptors in muscle tissue" and affects bone loss, potentially explaining the effectiveness of Vitamin D in fracture prevention.

Posted by Kristopher Foster on January 31, 2006 09:52 AM