Supplement sleuth

Better Nutrition, April, 2007 by Gary Bushkin

Q: Why do some vitamins and minerals like calcium come in so many forms?

A: Several factors influence a dietary supplement's form. In general, factors that determine the best form for a product include solubility, stability under heat, the ability to remain intact under the pressure of tablet-making, and the ease of disintegration in the stomach. Keep in mind that different forms of the same nutrient often have separate physical properties.

The source of vitamins, minerals or other nutrients is often an indication of quality. For instance, calcium, as calcium carbonate or oyster shell calcium, is less expensive, less bioavailable and oftentimes less effective than calcium citrate or other types of calcium.

Also, some vitamins have active and inactive forms. The body can use active forms almost immediately, without a conversion process. Vitamin B12 is a great example. Cyanocobalamin, the inactive form, is used in roughly 95 percent of B12 supplements; however, methylcobalamin is the active, most bioavailable and effective form.

The intended use of the supplement is also significant. For example, you would want to use the niacinamide form of niacin to promote overall health, but the nicotinic acid form if you want to lower your cholesterol.

Gary Bushkin, PhD, CNC, is a consultant for the natural products industry who specializes in the development of supplements and functional and natural foods. His books include FAQs: All About Green Food Supplements. Do you have a supplement question? Email it to editorial@betternutrition.com.