Not eating well? Neither are most American adults, according to a government study. And many think they can bridge the gap between their diet and a healthy one by depending on commercial supplements, vitamins, minerals, herbal extracts and more.

In the 1970s, only one in four adults took vitamins or other supplemental nutrients. Thirty years later, that number has jumped to slightly more than half of American adults.

However, study administrators did note that supplement use was associated with certain demographic characteristics. Adults with at least some college education use supplements more than those possessing solely a high school education. In fact, higher-educated consumers are:

• Twice as likely to take supplements than high school dropouts
• 70 percent more likely to take multivitamins and vitamin E than high school graduates
• Almost twice as likely to take vitamin C
• Almost twice as likely to take B-complex vitamins
• 50 percent more likely to take calcium

According to investigators, "the line between dietary supplements and foods or drinks is becoming very unclear."

Can Taking Supplements Harm You?

Researchers also looked at the potentially dangerous mix of taking supplements with prescription medications. On rare occasions, a combination of the two could produce a serious interaction.

Two specific supplements were looked at: garlic and St. John's wort.

While garlic is supposed to prevent heart problems and cancer, its enzymes can increase or decrease the strength of certain medications. In one study, it interfered with the effectiveness of an HIV drug.

St. John's wort is known for its use as a natural antidepressant. However, in studies it has been linked to decreased mobility in sperm and diminished potency of cancer drugs.

In fact, St. John's wort caused some transplant patients to reject their organs because it interfered with the immunosuppressive drug meant to help the body assimilate. Concentrations of the transplant drug dropped even when the dosage was increased.

Some other supplements contain toxic metals.

Lead has been discovered in some calcium pills and the now-banned ephedra weight-loss supplements have been found to contain mercury, cadmium, arsenic and uranium.

Science News September, 2004;166(10)

Dr. Mercola's Comments:

There is no question that supplements -- including vitamins and minerals -- can compensate for some of the damage that we do to ourselves. However, my experience is that many, if not most, people use the supplements to justify their poor choice of foods. No matter what you spend or what dosage you take, there is no substitute for proper eating. New patients I see frequently spend more than $4-500 a month on supplements, and some spend much more than that. Use the right food as your supplement and your body will be much healthier and much more likely to obtain the real benefits of the vitamin. People who eat according to their personal nutritional type often are happier and healthier, especially in the long term. Also, some supplements have been linked to serious health problems, particularly iron. Excess iron may lead to: Cancer Diabetes Parkinson's Disease Stroke In my nutrition plan, I address supplement use. As a general rule, I do not recommend most supplements. There are, however, a few supplements that do seem to make sense universally. They include: Vitamin D with exposure to sunlight and high quality fish oil. You also may chose to use Living Fuel Omega-3 and E. Vitamin K is absolutely essential to build strong bones and prevent heart disease, but it is "the forgotten vitamin" that many people do not get nearly enough of on a daily basis through the foods they eat. Related Articles: Fish Oil Lessens Cancer's Damage Folic Acid and Vegetables Build Stronger Bones Six Ways Garlic Can Improve Your Health Beware--Food is Your Medicine, Not Supplements Do You Really Need a Shopping Bag Full of Supplements? Supplement Regulation: Who's Behind It, and Why Should You Oppose It?