EVEN the most brazen snake-oil salesman might blush at trying to sell the public on a pill to ease aches and pains, strengthen bones, slow down cancer and prevent diseases as varied as Type 1 diabetes, multiple sclerosis and schizophrenia.
But these claims aren't the frothy hyperbole of a sideshow huckster. A growing number of serious scientists are quite willing to speculate that a single compound may be able to accomplish all of these feats -- and possibly more. They're not talking about a new miracle drug, but a common nutrient: vitamin D, "the sunshine vitamin."
Once seen as merely a defense against rickets, vitamin D has in recent years gained recognition as a major force that acts throughout the body. It improves absorption of calcium, controls the growth of cells (both healthy and cancerous), strengthens the immune system and seems to rein in overzealous immune system cells that cause diseases such as rheumatoid arthritis and multiple sclerosis.
Much of vitamin D's potential is still just that: potential. But at this moment, to some scientists the potential looks huge. "Even if two-thirds of these things don't pan out, it's still a blockbuster," says Dr. Robert Heaney, a professor of medicine at Creighton University in Omaha, who specializes in osteoporosis.
As excitement about vitamin D grows, so does the concern that many people may not be getting enough. In March, an article in the journal Mayo Clinic Proceedings called vitamin D deficiency "a largely unrecognized epidemic in many populations worldwide."
Heaney and many other researchers believe the Food and Drug Administration should consider radically increasing the suggested daily dietary intake of the vitamin, which is currently set at 200 international units (IU) for anyone younger than 51, 400 IU for people 51 to 70, and 600 IU for those 71 and older.
They cite studies such as one published earlier this year that found that cancer deaths were especially common in men with low levels of vitamin D, and a series of studies showing that high levels of vitamin D improved strength and prevented falls in elderly people.
"The daily allowances for vitamin D are outdated," says Anthony Norman, a professor of biochemistry at UC Riverside. "I would recommend 1,000 IU per day for all ages, with a maximum of 2,000 IU. I'm considering taking 2,000 IU myself." And, he adds, current evidence suggests that even 10,000 IU -- overkill by anyone's standards -- would probably be safe.
