Osteoporosis: Prevention

• Calcium
• Calcium Supplements
• Vitamin D
• Exercise for Healthy Bones
• Medications to Prevent and Treat Osteoporosis
• Fall Prevention

Vitamin D is needed for the body to absorb calcium. Without enough vitamin D, you will be unable to absorb calcium from the foods you eat, and your body will have to take calcium from your bones. Vitamin D comes from two sources: through the skin following direct exposure to sunlight and from the diet. Experts recommend a daily intake between 400 and 800 IU per day, which also can be obtained from fortified dairy products, egg yolks, saltwater fish and liver.

Vitamin D plays a major role in calcium absorption and bone health. The relationship between calcium absorption and vitamin D is similar to that of a locked door and a key. Vitamin D is the key that unlocks the door and allows calcium to leave the intestine and enter the bloodstream. Vitamin D also works in the kidneys to help resorb calcium that otherwise would be excreted.

Vitamin D is manufactured in the skin following direct exposure to sunlight. The amount of vitamin D produced in the skin varies depending on time of day, season, latitude and skin pigmentation. Usually 10-15 minutes exposure of hands, arms and face two to three times a week (depending on one's skin sensitivity) is enough to satisfy the body's vitamin D requirement. Use of sunscreen markedly diminishes the manufacture of vitamin D in the skin, as do window glass, clothing and air pollution. Skin color also affects vitamin D production; the fairer you are, the more you make.

As an adult ages, the ability to make vitamin D through the skin decreases. People who are housebound and experience no sunlight exposure are unable to make vitamin D.

Some calcium supplements and most multivitamins contain vitamin D, so it is important to check the labels to determine how much each contains. Experts recommend a daily intake of between 400 and 800 international units (IU). Do not take more than 800 IU per day unless your doctor prescribes it, since massive doses of vitamin D may be harmful.

Consult your physician before using any vitamin D supplement.