Americans keep taking their vitamins, according to a survey conducted by Ipsos-Public Affairs for the Council for Responsible Nutrition.

This year, 66 percent of U.S. adults label themselves as supplement users, up just slightly from 65 percent in 2009, according to the online survey said. That compares with 64 percent in 2008, 68 percent in 2007 and 66 percent in 2006.

Regular supplement use also remains steady: 74 percent of consumers classify themselves as “regular” users, compared with 21 percent who say they are occasional users and 5 percent who call themselves seasonal users. In 2009, 73 percent said they took supplements regularly; in 2008, 75 percent; and in 2007, 77 percent.

“It’s encouraging that during these tough economic times, consumers are maintaining their supplement regimens. It’s clear that year over year they still place value on these products,” said Judy Blatman, senior vice president, communications, CRN. “While we’d like to see these numbers grow over time, the fact that usage has remained steady reinforces the importance consumers place on dietary supplements.”

As a matter of fact, retailers see the down economy as part of the reason their supplement sales are continuing to stay strong.

At a recent Independent Natural Food Retailers Association buyers’ meeting, “everyone was speaking of their uptick in supplement sales,” said Dot Peck, program director for the association. “The economic effect seems to be pushing consumers towards supplements to maintain their health, with the high cost of healthcare.”

The survey also showed that more consumers are taking vitamin D than in previous years. According to the 2010 results, 27 percent of supplement users take a vitamin D supplement—up from 19 percent in 2009 and 16 percent in 2008.

“The ever-growing body of research on the benefits of vitamin D has been widely circulated in scientific journals, among healthcare practitioners and within popular press, so it’s no surprise that we are seeing more consumers adding it to their existing supplement routines,” Blatman said.

INFRA members also are reporting increases in sales of vitamin D supplements. Peck said one store in the Pacific Northwest mentioned diminished access to sunlight during certain times of the year as another reason.

“Other supplements being reported as steady and growing are probiotics, fish and flaxseed oil, calcium and multiple vitamins,” Peck said.

Consumer confidence in dietary supplements has also remained consistent in 2010, with 82 percent of adults indicating that they are confident in the safety, quality and effectiveness of dietary supplements. That compares with 84 percent in 2009, 81 percent in 2008, and 80 percent in 2007.