Several questions arise about vitamin/mineral supplements. First, are they necessary for everyone? If so, what are the appropriate amounts? And finally, are there significant differences in terms of purity and active ingredient delivery among products? Unfortunately, the first two questions cannot be answered in a simple fashion. There is no compelling evidence that a healthy person with a diverse diet benefits from a supplement, while there is plenty of evidence for appropriate use during pregnancy or for medical conditions ranging from osteoporosis to anemia. But there are also some caveats. High intake of calcium, for example, has been linked with prostate cancer, and vitamin K can interfere with the action of anticoagulant medication.
Many people take supplements as a sort of “nutritional insurance,” which is not unreasonable given that most probably do not have a balanced diet. Actually, there is no total scientific consensus on what constitutes a balanced diet. But many regulatory agencies around the world have made solid educated guesses about the amounts of vitamins and minerals in supplements that may deliver benefits without causing harm. Supplementing the diet with about 400 IU vitamin E, 1000 IU vitamin D and 500 mg calcium, for example, can be scientifically supported. The market is flooded with a plethora of such products, generally of similar quality.
ConsumerLab is an independent company that tests supplements and provides highly reliable information. After testing numerous products, a few were found to contain either more or less of some ingredients than listed on the label, but not by a significant amount. There was no lead contamination in any of the popular products — a previous worry. Supplements disintegrated equally, meaning that there was no difference in the release of the active ingredients. With calcium, there is some indication that calcium citrate may be better absorbed than the commonly used calcium carbonate. In the ConsumerLab evaluation, generic and store brands fared as well as the expensive brand names, suggesting that for “nutritional insurance” the most economic products are an appropriate choice.
