The use of dietary supplements has grown since the early 1990s, when it was about 42%, according to figures released by the Center for Disease Control and Prevention.

In the five years up to 2008, half of adults 20 and older were taking at least one dietary supplement. The biggest change was for calcium. Two-thirds of women aged 60 and over take it -- up from 28% in the early 1990s.

Data comes from national, in-home surveys in 1988-1994 and 2003-2008. The surveys in the past decade included more than 2,000 participants each year. Use of multivitamins, the most popular supplement, crept up to nearly four in 10 people taking the pills.

The survey suggests that most people who take vitamins and other supplements are educated, have good incomes, eat pretty well and already get the nutrients they need from their diets.

“It's almost like the people who are taking them aren't the people who need them,” said Regan Bailey, a nutritional epidemiologist with the National Institutes of Health.

The government supports some supplements as an option for certain people -- such as iron for women who are pregnant, folic acid for women thinking of getting pregnant and calcium for older women.

From the April 21, 2011, Prepared Foods' Daily News.