Diet & Fitness News

To Prevent Fractures, Vitamin D + Calcium

by Howard LeWine, M.D.
Harvard Medical School

Taking vitamin D pills reduces the risk of fracture in adults over 65. But this benefit occurs only if they also take calcium. That's the conclusion of a new study that put together the results of 50 prior studies. The report came from the U.S. Preventive Services Task Force. This is an expert group that provides advice on preventive care to health professionals. The journal Annals of Internal Medicine published the study. HealthDay News wrote about it December 19. The report author told HealthDay that the group could not advise specific doses. People in the studies reviewed took from 300 to 1,100 international units of vitamin D. The calcium doses they took daily ranged from 500 to 1,200 milligrams.

What Is the Doctor's Reaction?

Vitamin D is essential to maintain bone health. A below-normal blood level increases your risk of osteoporosis, falls and fractures. As many as 1 out of 3 people in the United States have low blood levels of vitamin D.

There are three main forms of vitamin D. The active form found in our bodies is 1,25-dihydroxyvitamin D. The body makes the active form from vitamin D2 and vitamin D3.

The skin makes vitamin D3 when it is exposed to ultraviolet light (sunlight). It is also found in foods and supplements. Vitamin D2 is found only in food and supplements. However, few natural foods are rich in vitamin D. That's why milk, orange juice and other products have vitamin D added.

Today, people get less exposure to sunlight, especially during the winter. Sun exposure also increases the risk of skin cancer and premature aging of the skin. So limiting sunbathing makes sense. We also absorb vitamin D less efficiently with age.

Vitamin D has taken over the role as the new wonder vitamin. Besides bone health, studies have shown that people with low levels of vitamin D may have an increased risk of cancer, high blood pressure, heart disease, stroke and other blood vessel diseases.

But it's way too soon to call it a wonder vitamin. No studies have proven that the low level of vitamin D causes any of these problems. Nor have they shown that taking vitamin D pills prevents them from occurring.

A new study provides some guidance on vitamin D use for the prevention of fractures and cancer. It found that vitamin D pills could help prevent fractures when combined with calcium pills. The researchers reviewed many studies. But they could not find enough evidence to conclude that vitamin D pills can help prevent cancer.

The U.S. Preventive Services Task Force commissioned the research. This is an expert group that provides advice on preventive care to health professionals. The journal Annals of Internal Medicine published the study's findings.

What Changes Can I Make Now?

This new study supports the current advice from the Institute of Medicine. The Recommended Dietary Allowance (RDA) for vitamin D:

• 600 international units (IU) a day for everyone ages 1 to 70
• 800 IU a day for those 71 and older

Personally, I recommend a daily pill containing 1,000 IU of vitamin D3. Some doctors suggest that this dose is too low. The Institute of Medicine says that up to 2,000 IU of vitamin D per day is safe.

To maintain bone health and prevent fractures, you need to get enough calcium. How much you need is debated because too much calcium taken as pills may be harmful. Recent studies suggest that high-dose calcium supplements might increase the risk of heart disease and certain types of cancer. Unlike calcium in your diet, calcium in pills also can cause kidney stones.

The current advice is 1,000 to 1,200 milligrams total calcium per day for adults. The recommended upper limit is 2,000 milligrams per day. Most people can easily get enough calcium through their diet.

What Can I Expect Looking to the Future?

There is no consensus today about routine testing for vitamin D blood levels. Experts debate what should be considered a normal value. Less than 20 nanograms per milliliter (ng/ml) is generally accepted as too low for whites but may be OK for dark-skinned people. To provide any other health benefits besides bone health, 30 ng/ml or even higher might be right.

Categories: Nutrition News, Senior Health

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