A disease long forgotten has made a resurgence in the U.S. Rickets, an affliction primarily affecting children deficient in vitamin D, softens bones and causes them to bend.

The cause of the recent outbreak, investigators believe, is the result of a reduction in children's consumption of cow's milk. Parents have instead been giving milk substitutes and breast-feeding. Cow's milk, however, has been fortified with vitamin D since the 1930s, which virtually eliminated the problem in the country.

In response to the growing problem, the Center for Disease Control is advising parents to be "more careful" about milk substitutes. This comes as the market for soymilk is booming. The International Dairy Foods Assoc. reports sales for pasteurized soymilk more than doubled their share of the refrigerated milk products market last year. In fact, one of the most popular milk substitutes--Silk soymilk--has seen sales almost triple over the past year. One more interesting tidbit: an eight-ounce glass of fortified milk contains 25% of the daily value of vitamin D recommended; according to its nutritional facts label, Silk contains 30%.