Vitamin D

Vitamin D is essential for healthy bones because it helps with the absorption of calcium. It may also help protect you against breast, prostate and colon cancer. Your skin can synthesize all the D you need provided you get about 15 minutes of sun three times a week. But as you grow older, you ability to manufacture vitamin D in the sunlight declines. By age 70 or older, you produce only 30% of the amount that you did when you were 25. In any case, many older people don't get much sun exposure if they are disabled or live in the northern latitudes. Others fear skin cancer and stay away from sunlight.

How much Vitamin D do you need?

• Birth-50 yrs: 200 I.U.
  
• 50-70 yrs: 400 I.U.
  
• 70+ yrs: 600 I.U.

In a study of older adults admitted to a Boston hospital, Thomas, Lloyd-Jones and colleagues (NEJM, 1998) found that nearly 60 percent of the elderly had low levels of vitamin D. The deficiency was common among many who had no obvious risk factors; one in three of those who took supplements were also deficient. Other studies indicate that at least one-third of the elderly with hip fractures were deficient in D. A French study examining the prevention of hip fractures found that nursing home residents who took supplemental vitamin D and calcium had a much lower probability of fracture.