U.S. researchers have concluded lower blood concentrations of vitamin D increase the likelihood of hip fracture among menopausal women by up to 70 percent.
In the study, which was published in the Aug. 19 issue of the Annals of Internal Medicine, researchers followed 800 women between the ages of 50 and 79 for an average of seven years (the mean age of the participants was 70). The women were selected from nearly 40,000 candidates who were not using estrogens or other bone-active therapies and, of those selected, 400 patients of the same sex and race had suffered hip fractures while 400 had not.
The University of Pennsylvania School of Medicine researchers concluded those women who had hip fractures had lower blood levels of vitamin D, specifically serum 25-hydroxyvitamin D.
“In our prospective, nested case–control study, we found that women with the lowest 25(OH) D concentrations (47.6 nmol/L) at study entry had a significantly greater risk for subsequent hip fracture during the next seven years than did women with the highest concentrations (70.7 nmol/L),” the researchers wrote.
They added that the correlation between vitamin D concentration and hip fracture was linear and unaffected by age. The number of physical falls did not differ between the control and active groups.
These results are consistent with the Third National Health and Nutrition Examination Survey, as well as with a 2005 cohort study conducted among Swedish women, which found those with 25(OH) levels below 52.5 nmol/L had twice the risk of hip fracture.
Limitations of the study included the fact almost all of the candidates were white and that bone density was not measured. The researchers did, however, test whether the vitamin D/hip fracture relationship was independent of poor physical functioning, frailty, falls, sex-steroid hormones, renal function or bone turnover. While more fractures were recorded among those with poor physical function and the frail, they found the relationship between 25(OH) levels and the likelihood of hip fracture was statistically significant.
Source: Nutra-Ingredients.com
