Although most people get the vitamins they need from the foods they eat, millions of people in America take supplemental vitamins as part of their health regimen.

Multivitamins are the most common dietary supplement taken regularly by at least one-third of American adults. The traditional role of a daily multivitamin is to prevent nutritional deficiency and there are good reasons to consider taking vitamin supplements.

The American Academy of Family Physicians recommends taking them for certain health problems, if you eat a vegetarian or vegan diet and if you are pregnant or breastfeeding.

Besides those scenarios, there may be no good reason for taking daily multivitamins.

Randomized studies have now essentially debunked the naïve belief that all vitamin and mineral supplements are good for health, regardless of the dose.

The first shock came from the discovery that high doses of betacarotene, compared to placebo, increased lung cancer risk among smokers. Then came the evidence that vitamin E was ineffective for preventing cardiovascular diseases or cancer, and at high doses could even be life-threatening.

Finally, there are the continuing, sobering, negative results for high doses of multivitamins and multi-mineral supplements for all types of indications.

In a large clinical trial, medical scientists investigated the benefits of multivitamin supplementation and the risk of cancer events.

The results, published in the Journal of the American Medical Association, found that, while daily multivitamin supplementation had no effect on the risk of cancer for healthy participants, daily multivitamin use was associated with a reduction in cancer among men with a baseline history of cancer (27 percent fewer new cancers).

The same trial reported that daily multivitamins had no effect on the risk of cardiovascular disease, including no reduction in heart attack, stroke or death from cardiovascular disease among men taking multivitamins, compared to placebo.

The majority of previous research has found no benefit for the routine use of multivitamin supplementation. A quality study examined the effects of dietary supplements to prevent chronic disease in over 38,000 women.

This study found that dietary vitamin and mineral supplements were associated with increased total mortality risk. Other reports from the Cancer Prevention Study-II suggest that multivitamin use is associated with a higher risk of fatal prostate cancer in men.

Dietary supplements are broadly used and are generally considered safe. But they are not always risk-free, especially taken in large quantities. More is not always better.

Check with your doctor, pharmacist, registered dietitian or healthcare provider before using a supplement. Caution is especially important for those who are pregnant, nursing a baby, diabetic, prone to hypertension or heart disease, or under 18 years of age.

The theory behind the use of multivitamins is good. However, the evidence does not support vitamin use for primary prevention. The most sensible approach is to maintain a balanced diet that includes reasonable amounts of fruits and vegetables.

We know that diets high in fruits and vegetables are associated with decreased risks of many chronic diseases and are without adverse effects.

Dr. Hari Dass Khalsa is a chiropractor with offices located in the Hawthorne District. Call 503.238.1032 for more information.

Editor’s note: Wellness Word is an informational column which is not meant to replace a healthcare professional’s diagnosis, treatment or medication.