D Is for Strong Bones

Up until now, vitamin D has been better known for its ability to promote bone strength by increasing calcium absorption. Supplemental vitamin D has been shown to reduce hip fracture risk among elderly women when combined with supplemental calcium. In one study of 3,270 healthy women, mean age 84, 1,634 received 1.2 g calcium and 800 international units (IU) vitamin D3, while the other 1,636 received placebo. During the 18-month study, the supplemented group experienced 43 percent fewer hip fractures, 32 percent fewer nonvertebral fractures, and a 2.7 percent increase in bone density of the proximal femur vs. the 4.6 percent bone density decrease seen in the placebo group.⁶

Other studies bear out vitamin D's importance to bone health, to the point where it's now widely known that vitamin D deficiency is associated with hip fractures, and supplementation helps. Unfortunately, not everyone is getting enough vitamin D. A recent study reveals that about 10 percent of retirees in Boston social clubs are vitamin-D deficient (< 15ng/mL serum vitamin D) compared with 21 percent of hip-fracture patients at the Massachusetts General Hospital.⁷ So experts now suggest people take 600 IU vitamin D daily, and up to 800 IU a day for elderly patients who do not produce vitamin D from sun exposure as easily as they did when younger.⁸ A recent study showed that 37 percent of adult hospital patients were deficient in vitamin D upon admission. Two-thirds of these patients did not consume enough vitamin D from dietary sources. Surprisingly, 46 percent of those who took daily multivitamins (most of which provide 400 IU) were also in a state of deficiency.⁹