(2 of 7)
"The field is currently undergoing a paradigm shift," says Catherine Woteki, director of the food and nutrition board at the Institute of Medicine of the National Academy of Sciences. "We are now entering the second wave of vitamin research," explains Jeffrey Blumberg, associate director of the Human Nutrition Research Center on Aging at Tufts University. "The first wave was the discovery of vitamins and their role in combatting nutritional deficiencies such as rickets and beriberi. That occurred in the first half of the century. Now we're on the second wave. You don't need to take vitamin C to prevent scurvy in this country today. But you could need it for optimal health and the prevention of some chronic disease."
Scientists have so far identified 13 organic substances that are commonly labeled vitamins. In the human body, they play a vital role in helping regulate the chemical reactions that protect cells and convert food into energy and living tissue. Some vitamins are produced within the body. Vitamin D, for example, is manufactured in the skin during exposure to sunlight, and three other vitamins (K, biotin and pantothenic acid) are made inside the human gut by resident bacteria. But most vitamins must be ingested.
Mystique and faddish lore have long surrounded these essential biochemical ; compounds. Consider vitamins C and E. "Somebody has made practically every claim you could dream of about these vitamins," points out John Hathcock, chief of the experimental-nutrition branch of the Food and Drug Administration. People have been gobbling vitamin C for 20 years in the certainty that it can cure the common cold, though evidence is still lacking. Vitamin E has been wildly popular for four decades because of its putative power to enhance sexual performance. In fact, studies indicate only that it is necessary for normal fertility in lab animals.
More recently, B6 has won favor as a relief for premenstrual syndrome. Vitamin A is touted as a rejuvenator by people who mistakenly believe that it, like its synthetic relative Retin-A, can give wrinkled, mottled skin that youthful rosy glow. "We never know what next year's fad is going to be," says Hathcock.
It is just this whiff of quackery that made vitamins a research backwater for years. Most reputable scientists steered clear, viewing the field as fringe medicine awash with kooks and fanatics. A researcher who showed interest could lose respect and funding. Certainly Linus Pauling lost much of his Nobel-laureate luster when he began championing vitamin C back in 1970 as a panacea for everything from the common cold to cancer. Drug companies too have been leery of committing substantial energy and money to studies, since the payoff is relatively small: vitamin chemical formulas are in the public domain and cannot be patented.
But attitudes have been shifting over the past few decades. Despite all the sneering, Pauling's speculations did get more scientists thinking about vitamins' impressive powers. As a class of compounds, they are known to produce hugely dramatic effects when missing from the diet: scurvy, pernicious anemia, rickets. What other exciting properties might they -- or related compounds -- have?