Quality Problems With Some Vitamin A Supplements

Vitamin A, also called retinol, is a fat-soluble vitamin that plays a role in a variety of functions throughout the body: vision, bone growth, immune function, reproduction, cell differentiation, and cell division. It also has antioxidant properties which neutralize free radicals, known to cause tissue and cellular damage. Liver, dairy products and cod liver oil are good sources of vitamin A and, because vitamin A is stored in the body’s fat for a long time, a deficiency is rare in the United States, but more common in developing nations where malnutrition is common. However, for Americans who limit their intake of vitamin-A-containing foods, a supplement may be needed. Vitamin A supplementation may also slow the progression of macular degeneration, enhance healing after laser eye surgery, and reduce the risk of certain cancers.

Because the U.S. Food and Drug Administration (FDA) does not strictly regulate herbs and supplements, there is no guarantee of strength, purity or safety of these products and effects may vary. Recent testing of vitamin A supplements, including beta-carotene and cod liver oil, by ConsumerLab.com, revealed quality problems with some vitamin A supplements. ConsumerLab.com is a leading provider of independent test results and information to help consumers and healthcare professionals evaluate health, wellness, and nutrition products.

Overall, ConsumerLab.com tested 16 products. Brands tested include Country Life, Ethical Nutrients, Garden of Life, Health from the Sea, Metagenics, Nature Made, Nature’s Bounty, Nature’s Way, Puritan’s Pride, Rite Aid, Solgar, Source Naturals, Spectrum Essentials, Swanson, Vitamin Shoppe, and Vitamin World. Six vitamin A supplements passed the testing, including tablets and oils, along with six other supplements tested through ConsumerLab.com’s Voluntary Certification Program. Among the ten supplements selected for testing, three provided significantly less vitamin A than stated on the labels, and one delivered nearly double its claimed amount of vitamin A, of concern due to potential toxicity. Toxicity with vitamin A, commonly sold as retinyl palmitate and referred to as preformed vitamin A, can occur at doses only moderately higher than required to prevent deficiency.

The three supplements that were low in ingredient contained only 68.2 to 77.5 percent of their claimed amounts of vitamin A (as retinyl palmitate and/or beta-carotene). Tests of one cod liver oil supplement showed it to contain 7,818 IU of vitamin A as retinyl palmitate, nearly double its claimed amount of 4,000 IU per teaspoon. Such a product should be avoided by pregnant women who, according to March of Dimes, should not exceed 5,000 IU per day due to the risk of birth defects. It should also be avoided by children under 13 years old, whose daily intake should not exceed 2,000 IU to 5,666 IU of preformed vitamin A, depending on their age, based on upper tolerable intake levels established by the Institute of Medicine. Vitamin A excess has been associated bone and liver abnormalities, as well as birth defects of the brain, eyes and head. Adults experience less specific symptoms such as headache, dizziness, fatigue, blurry vision, bone pain and swelling, nausea and/or vomiting. Beta-carotene, or pro-vitamin A, does not carry this toxicity.

The complete, detailed report, which includes extensive information about how to buy and use vitamin A supplements and potential side effects, is available here at Consumer Lab.