New vitamin D recommendations

By Rob Stein
Tuesday, November 30, 2010; 9:11 AM

Despite mounting pressure to urge many Americans to sharply boost their vitamin D levels, new government recommendations are not advocating a huge increase in the amount of the "sunshine vitamin" that people get.

The United States and Canada asked the Institute of Medicine, which is part of the National Academy of Sciences, to update the official vitamin D recommendations for the first time since 1997. A 14-member expert committee convened for the task concluded that most Americans and Canadians up to age 70 need no more than 600 international units of vitamin D per day. The elderly may need as much as 800, the committee concluded.

Previously, experts called for children and younger adults get 200 international units a day, adults ages 50 to 70 get 400 and the elderly to get 600. But a flurry of research indicating that vitamin D may have a dizzying array of health benefits, and that many people may have insufficient levels, had reignited an intense debate over whether federal guidelines were outdated, leaving millions unnecessarily vulnerable to heart disease, cancer, diabetes, infections and other ailments. Some have been advocating that doctors routinely test their patients' vitamin D levels and that people should routinely consume 2,000 or 3,000 international units a day.

After reviewing nearly 1,000 published studies along with testimony from scientists and others, the expert committee concluded that vitamin D and calcium play an important role in creating strong bones. But the committee concluded that while further research was warranted into the nutrient's role in other health issues, at this point the evidence is mixed and inconclusive. The committee noted that other nutrients, such as vitamin E, were thought to have a host of health benefits, an idea which was later disproved and in some cases found to be dangerous.

So the committee recommended that 600 international units a day met the need for almost everyone in the United States and Canada, though people age 71 and older may need as much as 800. The committee also concluded that available evidence does not indicate there are widespread deficiencies, as some have suggested, requiring routine screening.

In addition, contrary to what some vitamin D proponents have been urging, the committee did not recommend people increase their sun exposure, citing concerns about skin cancer.

Scientists have long known that vitamin D is a vital nutrient that the skin produces when hit by sunlight. The amount varies, depending on where the person lives, skin pigment, age and other factors. With people spending more time indoors and covering up and using sunblock when they do go outside, the amount of vitamin D people create in their bodies has been thought to be falling.

But the committee concluded that most people can get sufficient vitamin D from their diets or by taking vitamin D supplements. Milk and other foods are fortified with vitamin D and it occurs naturally in others, such as fatty fish.

The recommendations disappointed many proponents of higher vitamin D intakes. Michael Holick of Boston University, one of the leading proponents of the supposed benefits of vitamin D, said he was pleased that the committee recommended higher levels than the previous guidelines. But Holick and others argue that there is more than enough evidence to support taking much more on a routine basis to reduce the risk for a host of health problems. Holick, for example, says he personally takes 3,000 international units a day and advises his patients to do so as well. Holick noted that the committee increased the upper limit of what was considered a safe level of vitamin D to 4,000 for adults.

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