Consumers spend millions of dollars on vitamins and other dietary supplements each year. Like over-the-counter medications, many vitamins and supplements are available in brand and off-brand versions, so it is possible to save money by comparison shopping.

Vitamins aren't regulated as tightly by the Food and Drug Administration as OTC or prescription medications. Instead, as a dietary supplement, they are regulated in a manner similar to food. Information about how the FDA regulates vitamins can be found on the FDA's Web site.

A dietary supplement must have a nutrition label that reveals its ingredients. Examining the label can tell you whether two vitamin, mineral or dietary supplement products have identical ingredients. If they do, it makes sense to buy the product that costs less.

The American Academy of Family Physicians notes that it is better to get needed vitamins and minerals through your regular diet than through dietary supplements and presents information about specific types of vitamins for varying populations such as children, seniors and women at www.familydoctor.org.

Other guides to vitamins and dietary supplements can be found at The Mayo Clinic Web site and the Harvard School of Public Health.