The Other Cause of Osteoporosis

An estimated 25 million Americans suffer from osteoporosis. The disease causes about 1.25 million skeletal fractures occur annually—300,000 of them hip fractures. About 30–35 percent of people with hip fractures will die within a year. Too little calcium can cause osteoporosis, but what many people don't know is that lack of vitamin D is also to blame.

Vitamin D is crucial in maintaining blood calcium in the normal range, yet a study at the Massachusetts General Hospital found that 30 to 40 percent of the adults over 50 tested were deficient in vitamin D. Without adequate levels of this vitamin, the body does not get enough calcium, no matter how much calcium is consumed. If inadequate calcium is absorbed, it is stolen from the bones, because calcium is continually needed for critical bodily functions.

Why are so many people vitamin D deficient? Most foods have little or no vitamin D. Milk is fortified with the vitamin, but many people do not drink milk. Ice cream, yogurt and cheese lack vitamin D. Cod liver oil and some fatty fish are the only rich natural food sources, but they must be eaten two or three times a week to get enough vitamin D.

A second cause of vitamin D deficiency is lack of sunlight. Many people do not get much sun, and those that are out in the sun often wear sunscreen, which blocks vitamin D production in the skin. The amount of sunlight necessary depends on the time of the year and geographical location. In Boston, the sunlight is not strong enough to make vitamin D from November to February, but residents of Los Angeles can make vitamin D year round. Experts recommend exposing hands, face and arms to sunlight two to three times per week, in an amount equivalent to 50–70% less sun than would cause sunburn. For example, if you would get sunburn after 30 minutes on a particular day, stay out for five to ten minutes without sunscreen to get your vitamin D quotient.

For elderly people, the 400 IU of vitamin D found in many multivitamins may not be adequate. Researchers recommend that older folks walk outside frequently. Walking gets them out in the sun, and also helps to maintain bone strength and increase muscle tone.   Based on information in: Nutrition Action Healthletter, Oct 1997