Uncertain Verdict as Vitamin D Goes On Trial

Researchers studying the connection between tuberculosis and vitamin D have become convinced that the compound can not only help treat TB but also prevent it. Some are part of a vocal camp of scientists see vitamin D as something of a cure-all—or rather a prevent-all. In addition to its well-established benefits for bone health, they say vitamin D may—with little or no side effects—be able to ward off colds and other infections and cut the risk of asthma, diabetes, cancer, heart disease, and other chronic diseases. Some of these scientists advocate fortifying more foods with the vitamin and advising people to take supplements and get more sun exposure. But others warn that the benefits of vitamin D are far from proven.