Vitamin D deficiency is associated with bone loss and bone fractures, which are major causes of disability and death among elderly women. Semba et al. conducted an observational study on the prevalence of vitamin D deficiency in two groups of elderly women aged 65 to 95 years. One group (1002) was comprised of women with varying degrees of disability from mild to severe, and the other group (436) of women with little or no disability. Vitamin D deficiency was prevalent in both groups, with a tendency for the more-disabled women to have lower serum concentrations of vitamin D than the less-disabled women. Women with the most severe degree of disability had significant risk factors for vitamin D deficiency, including increased age and black race.
All participants were part of the Womens Health and Aging Study in Baltimore. The more-disabled women were somewhat older than the less-disabled group. Serum concentrations of 25(OH)D, the major circulating form of vitamin D, were measured. The results suggested that vitamin D deficiency is common in older community-living women and is associated with higher levels of disability. Specifically, 14% of the women who were categorized as the most-disabled were vitamin D deficient, while only 6.8% of women who reported no disability were deficient. Elderly black women had a higher incidence of vitamin D deficiency than did white women. The elderly black womens increased risk for vitamin D deficiency could be due to lower cutaneous synthesis of vitamin D3 as a result of increased skin pigmentation. Obesity was associated with vitamin D deficiency in the less-disabled group but not the more-disabled group. In the less-disabled group, obesity may have been more of a defining factor because of its effect on outdoor activity and exposure to sunlight.
The authors conclude that elderly black women are at significant risk for bone loss, bone fractures and disability due to vitamin D deficiency, and that clin
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American Journal of Clinical Nutrition