(HealthScoutNews) -- Ever since "I Love Lucy" gave us the classic "Vitameatavegemin" episode, vitamins have been a household word.

Indeed, studies published recently by the National Center for Environmental Health found that each year Americans spend up to $1.7 billion on vitamin supplements, making them the third most popular over-the-counter drugstore buy.

But, how many of us know what we're really getting when we purchase supplements? Experts say too often we may be buying far more "good health" than we really need.

"When a multi-vitamin contains an overabundance of nutrients, or is packed with herbs along with vitamins and many different minerals, we're not getting the bargain we think we are," says Dr. James Dillard, an assistant professor of medicine and medical advisor at the Rosenthal Center of Alternative and Complementary Medicine at Columbia University.

The reason, he says, is "a tablet or capsule can only hold so much. And the greater the number of different ingredients you put into a single pill, the less of each individual ingredient you can have, sometimes to the point where there is so little of each nutrient, the pill is hardly worth taking."

That can hurt in other ways as well -- particularly when you think you're getting more protection than you really are. This can be especially true for women when the mineral is calcium, says registered dietician Samantha Heller.

"Calcium should always be taken as a separate supplement, as they simply can't fit all a woman needs into one multivitamin pill," says Heller, a nutritionist at New York University Medical Center. Buying a vitamin/mineral supplement that boasts a complete nutrient package can be misleading, she says -- particularly to women.

Vitamin supplements with nutrient levels that soar above the recommended daily amounts (RDA) can also cause problems, increasing the risk of a variety of unpleasant side effects, including diarrhea and nausea, Heller says. Excessive doses of vitamins A and D, for example, can even have some serious toxic effects, she says.

How you feel after you take your vitamins should also influence your choice of products as well. While many people mistakenly believe that something as healthy and natural as a vitamin pill can't make you feel sick, the fact is, it can.

According to Dillard, nuances in the way vitamins are manufactured, or even the source of the nutrients themselves, can affect the way you react to any specific supplement. That can result in everything from dizziness to headaches, fatigue, hives or other allergic-type reactions.

"If you take a vitamin supplement and don't feel well, switch brands. You might be surprised to see a real difference in how your body reacts," Dillard says.

When it comes to choosing a brand of vitamin, many experts say name recognition counts -- with the bigger, more experienced companies more likely to give you a higher-quality product.

"The bigger companies that do nothing but manufacture vitamins, they simply can't afford to give you an inferior product," Dillard says. "And I don't know if that can be said for lesser known, or private-label companies, like supermarkets that package their own brand of supplements."

Also important: Seeking a product with no sugars, starches, binders or fillers of any kind.

Another key concern -- making certain the nutrients you do take get into your bloodstream, a goal that's often defeated when supplements carry the equivalent of a bullet-proof vest in the form of a hard shell coating.

"If we X-ray someone's stomach, we can often see dark shadows indicating undissolved vitamin pills that were consumed many hours before," Dillard says.

To help ensure that vitamins do dissolve quickly and completely, look for products that carry the U.S. Pharmacopeia seal of approval, usually noted as "U.S.P. Approved" on the label. That means the product was tested by a government agency and found to dissolve in a minimum amount of time.

Because seeking U.S.P. approval is a voluntary action, not all companies do it -- or comply with the agency's recommendations. It's also true that some companies that don't seek U.S.P. approval do make vitamins with a high dissolution rate.

How's a consumer to know? All you need is vinegar and water to find out.

According to Dillard, simply mix equal parts of water and vinegar in a glass and drop in your vitamin pill. Within 40 minutes, it should be well on its way to being dissolved. If it's not, he says, it's probably going to pass through your body undigested.

Finally, always check the expiration date before buying a vitamin supplement. If you don't find one, don't buy the product. If you do find one, you should be able to finish the bottle before the expiration date.

What To Do

For more information on how to find quality vitamins, visit WomenToday.com. To learn how to choose supplements wisely, visit North Dakota State University.

To find out what to look for in all dietary supplements, including not only vitamins and minerals but also herbs and other nutritional products, visit the U.S. Food and Drug Administration.

Reference Source 101

For more information on how to prevent other diseases, use
PreventDisease.com's "Quick Prevention Resources".