November 3, 1997
Contact:
Mary Burnette
202-872-1488
[email protected]
MOST MULTIVITAMIN PRODUCTS MEET USP DISSOLUTION TEST TUFTS MISINTERPRETS SIGNIFICANCE OF THE TEST
There is no established correlation between the U.S. Pharmacopeia (USP) dissolution test and the body's ability to absorb multivitamin supplements. None the less, The Tufts University Health and Nutrition Letter tries hard to make a story out of the fact that two out of ten brands of multivitamins failed to pass a USP dissolution test.
The real story is that all of the products which claimed to meet USP standards passed the test. So did most of the products which made no label claim about meeting USP specifications. USP is an independent standard setting body for medical and related products. USP has recently established voluntary standards for multivitamin and mineral supplements which include a number of criteria in addition to the dissolution test.
The Tufts newsletter incorrectly suggested that failing the dissolution test indicates that a product will not be absorbed by the body. This is simply not true and no correlation should be drawn between the two. The USP dissolution test is a simplified laboratory test which does not accurately replicate the conditions that exist in the gastrointestinal tract. The newsletter itself points out that "there is no test tube procedure sophisticated enough to mimic all the chemical reactions that occur in the absorption process." Just because a product fails a laboratory test doesn't mean it won't dissolve in the body and be absorbed. Scientific studies sponsored by the industry have been conducted to determine whether there is any correlation between a product's performance on the USP disintegration (product's ability to fall apart) or dissolution tests and its actual bioavailability in humans. Nutrients analyzed included vitamin C and riboflavin. Formulations that performe! d well on USP's disintegration and dissolution tests were not the ones best absorbed in the body.
Human studies show unequivocally that vitamin and mineral supplements are well absorbed. In virtually every clinical or epidemiological study that has been done, supplement users have been shown to have higher blood levels of vitamins and minerals than non-users. This demonstrates that the products are indeed being absorbed by the body.
To cite just one example: A study published this year in the American Journal of Epidemiology showed that women who used prenatal multivitamins had increased blood levels of folic acid (a B vitamin) and ferritin (an indicator of iron status). The women who used supplements were much less likely to have preterm delivery or low birth weight babies. Results like this could only be possible if the products were indeed dissolving and being absorbed.
USP is still in the process of perfecting appropriate testing methods for vitamins and minerals, and the industry is cooperating in this effort. The dissolution test is relatively new, and some companies are formulating their products to meet the standard even though they recognize that it does not necessarily reflect a product's ability to be absorbed by the body.
The bottom line is that consumers can be confident in their vitamin and mineral supplements. The scientific evidence shows that they are being dissolved and absorbed in the body, where it counts, and that these products are indeed helping health-conscious consumers optimize their health.
###
RSS