ConsumerLab.com found that among the 41 multivitamins sold in the U.S. and Canada (including three products for pets) which it selected for review, 13 failed to pass tests necessary to obtain ConsumerLab.com approval. Several products also exceeded tolerable intake limits established by the Institute of Medicine for nutrients such as niacin, vitamin A, folate and magnesium. Exceeding these levels puts one at increased risk for side effects and toxicities, although this may be appropriate in certain situations. Higher price did not mean higher quality: Many inexpensive multivitamins (costing less than 10 cents per day) passed all tests and gained approval, while several more expensive products (costing more than 40 cents per day) failed to be approved.
ConsumerLab.com tested multivitamins for key water-soluble and fat-soluble vitamins, minerals, contamination with the heavy metals lead, cadmium, and arsenic, and checked for proper labeling. Tablets were also checked to make sure they would disintegrate properly.
Key findings, by type of multivitamin product:
General Adult: Several quality, all-around multis were identified, costing as little as 3 cents per day. However, one product was found to contain only 17% of its listed folic acid, an important B vitamin.
Women's: Several quality, all-around multis for women were identified, costing as little as 4 cents per day. However, one product was found to contain only 17.5% of its listed vitamin A.
Women's 50+: A quality, all-around women's 50+ multi was identified, costing only 3 cents per day. However, one product was found to contain 20% less vitamin A than listed and 41% more calcium than listed.
Prenatal: Two quality prenatals were identified which provided the 800 mcg of folic acid recommended to help prevent neural tube defects and 150 mcg of iodine recommended for proper brain development. Although no prenatal vitamin failed to contain listed ingredients, many lacked the recommended iodine.
Men's: A quality, all-around men's multi was identified which cost only 3 cents per day. However, a men's multi failed to properly disintegrate — requiring more than twice the allowed time to break apart in solution.
Men's 50+: The one product tested in this category contained only 58% of its listed vitamin A.
Children's: A quality children's gummy multi was identified, costing only 8 cents a day. However, it did not include iron in its formulation (likely out of concern for iron toxicity if over-consumed as a candy by children). Most children are not iron deficient, but, particularly for adolescent girls, iron is important—see the "Teen" section below. One children's multi contained only 28% of its listed folic acid, providing much less than the recommended intake for children. Another product contained 74% more folate than listed, but the listed amount was small and this is not a health risk.
Teen: Several quality multis for teens were identified, although all provided higher than recommended amounts of certain nutrients. Adolescent girls may be better off taking a moderate-dose women's multi, with iron and calcium. Adolescent boys may be better off taking a general multi which includes iron, as they need more iron than younger children and men. One teen multi contained only 40% of its listed vitamin A and 48% more calcium than listed.
Pet: None of the pet multivitamins were approved: One contained only 30% of its listed vitamin C; one had only 16% of its vitamin C and 8% of its vitamin D; and one contained only 52% of its listed vitamin A.
Two specialty multis, one for people with diabetes, and one for people who have undergone bariatric surgery, were also tested and approved, although they may not be ideal for all such people, as noted in the report.
Dr. Cooperman says consumers should take stock of their personal nutritional needs before considering a multivitamin. "If you need nutritional support from a multi, it's possible to get it from a good, safe product for just pennies a day," he said.