Vitamin intake and bone health are closely linked, new research confirms. In one study, older women who took combined vitamin K and D plus calcium for two years showed a "modest but significant" increase in bone mineral content (BMC) at the wrist, a standard site for testing.
Another study found that "the high prevalence of vitamin D deficiency among Aboriginal women, combined with lower dietary intake of calcium, especially in older women, likely contributes to the higher incidence of fracture in this population."
The first study involved about 250 healthy Scottish women, age 60 and up. The women were randomly assigned to take daily a placebo; or separate tablets of vitamin K, vitamin D, and calcium; or combined vitamin K and D plus calcium.
Women who took combined vitamin K and D plus calcium "showed a significant and sustained increase in both BMD [bone mineral density] and BMC at the site of the ultradistal radius [wrist]," the researchers found.
In the Aboriginal study, conducted by the University of Manitoba, 183 urban and 26 rural Aboriginal women and 146 urban white women completed a dietary questionnaire. Urban Aboriginal women had a lower dietary intake of calcium than urban white women, the researchers found.
As well, based on blood tests, 32% of rural Aboriginal women and about 30% of urban Aboriginal women were vitamin D-deficient. By comparison, about 19% of urban white women were vitamin D-deficient.
Sources: J Bone Miner Res. 2007 Apr;22(4):509-19; J Nutr. 2007 Feb;137(2):461-5