Unlike prescription drugs, vitamins and supplements are not subject to FDA approval or its regular testing of any kind. So how do you know what’s really in your vitamins? I started ConsumerLab.com in 1999 to answer this question. Since then we have tested and reported on the quality of well over 3,000 products. We have found problems with about 25% of the supplements we have tested. Important questions we look to answer when we test and review products include:
- Do the products have the key ingredients that they claim to have?
- Do they products have too much of an ingredient? (Some ingredients can be harmful in larger amounts)
- Are the products contaminated with heavy metals like lead?
- Do pills break apart properly so your body can absorb the contents?
ConsumerLab.com’s Latest Multivitamin Tests
As we shared with Dr. Oz., our most recent tests found problems with the quality of nearly 40% of the multivitamins we selected to test. The problems (all confirmed by a second laboratory) include:
- An adult chewable multivitamin had nearly 2.5 times its claimed amount of vitamin A in the retinol form. Getting too much of this type of vitamin A can be harmful, causing bone weakening and even liver toxicity.
- A dozen multivitamins, including senior, adult, prenatal and teen products, provided less vitamin A and/or folic acid than claimed, some with less than 30% of the listed amounts.
- Tablets of two different products would not break apart within the required 30 minutes, indicating that they may not fully release all of their ingredients for absorption.
In addition, more than 30 products exceeded, or were right at, upper tolerable intake levels for various vitamins or minerals. Exceeding these levels puts you at increased risk for various side effects or toxicities, and should be avoided unless higher levels are recommended by your physician to treat certain medical conditions. For example, large doses of niacin are often prescribed to people with high cholesterol, but this can also cause skin flushing and tingling. As noted earlier, excess pre-formed vitamin A may lead to liver abnormalities and bone weakening. Excess zinc can cause immune deficiency and anemia.
On a positive note, we also identified many high-quality multivitamins – some of which cost as little as 3 cents per day!
You can get access to ConsumerLab.com’s Multivitamin Review using the 24-hour pass being offered to Dr. Oz viewers. Review the Consumer Tips sections for each vitamin and mineral for more information about upper limits and product tests.
ConsumerLab.com’s recent tests of calcium and vitamin D supplements, also mentioned on The Dr. Oz Show, showed that some popular products contained about 70 to 80% more vitamin D than listed (which can be a health concern, as too much vitamin D may reverse some of the benefits of vitamin D). One calcium/vitamin powder was contaminated with lead. The amount found was small but exceeds California’s strict limit of 0.5 mcg per daily serving – above which a warning label is required. Although the amount of lead in this product is not an immediate danger, lead is stored in the body, replacing calcium in the bones. Lead can raise blood pressure, affect cognitive function, and even lead to brain damage in children. For these reasons, it is best to avoid lead exposure whenever possible. Fortunately, our testing found many other products that did not have this level of lead contamination.