Getting the right amount of vitamin D every day is so important for everyone, from kids to the elderly, folks will turn to a supplement when they can't get enough of the right mix of foods in their diets and safe sunshine exposure.

Unfortunately, taking a supplement offers no guarantee that a patient will receive enough vitamin D to make a real difference in his or her health, according to an analysis of over-the-counter (OTC) supplements presented at last month's meeting of the America's Committee on Treatment and Research in Multiple Sclerosis in San Antonio.

While comparing 10 brands of OTC supplements (from online and brick-mortar stores) with stated dosages ranging from 400-10,000 IU, scientists discovered actual amounts of vitamin D varied wildly from a low of 0.24 percent to 81.7 percent, averaging 33.5 percent across the board. With one ridiculous exception, the higher the labeled dosage, the greater the disparity in the actual amount of vitamin D. (One OTC supplement contained 0.24 percent of the 400 IU it was supposed to have.)

Just another reminder that you can't always count on a label to give you the straight scoop about the quality of a supplement, which is why we recommend that you do your homework, starting with CNCA’s Nutritional Supplement Quality -- The Facts.

MedPage Today June 7, 2010