Vitamin D is being added to more and more foods, said Paul R. Thomas of the Office of Dietary Supplements at the National Institutes of Health. Not only is it in orange juice and milk, but more is being added to breakfast cereals, and it now can be found in very high doses in supplement pills. Most vitamin D pills, he said, used to contain no more than 1,000 international units of it. Now it is easy to find pills, even in places like Wal-Mart, with 5,000 international units. The committee, though, said people need only 600 international units a day.

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To assess the amounts of vitamin D and calcium people are getting, the panel looked at national data on diets. Most people, they concluded, get enough calcium from the foods they eat, about 1,000 milligrams a day for most adults (1,200 for women ages 51 to 70).

Vitamin D is more complicated, the group said. In general, most people are not getting enough vitamin D from their diets, but they have enough of the vitamin in their blood, probably because they are also making it naturally after being out in the sun and storing it in their bodies.

The American Society for Bone and Mineral Research and other groups applauded the report. It is “a very balanced set of recommendations,” said Dr. Sundeep Khosla, a Mayo Clinic endocrinologist and the society’s president.

But Andrew Shao, an executive vice president at the Council for Responsible Nutrition, a trade group, said the panel was being overly cautious, especially in its recommendations about vitamin D. He said there was no convincing evidence that people were being harmed by taking supplements, and he said higher levels of vitamin D, in particular, could be beneficial.

Such claims “are not supported by the available evidence,” the committee wrote. They were based on studies that observed populations and concluded that people with lower levels of the vitamin had more of various diseases. Such studies have been misleading and most scientists agree that they cannot determine cause and effect.

It is not clear how or why the claims for high vitamin D levels started, medical experts say. First there were two studies, which turned out to be incorrect, that said people needed 30 nanograms of vitamin D per milliliter of blood, the upper end of what the committee says is a normal range. They were followed by articles and claims and books saying much higher levels  40 to 50 nanograms or even higher  were needed.