About half of U.S. adults take vitamins and other dietary supplements — a level that’s been holding steady for much of the past decade, new government figures show. But the data also show a booming number of older women are taking calcium, says the Natural Products Association. According to U.S. government officials, the use of dietary supplements has grown since the early 1990s when it was about 42%. The data shows use leveled off in 2003 through 2008, with about half of adults 20 and older ...