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.
Simple Things You Can Do to Buy a Better Vitamin
Tip 1: Test your vitamin at home.
The best vitamin in the world won’t do you much good if it doesn’t release its ingredients. Pills that don't disintegrate properly may not release all of their ingredients for absorption, and ingredients may go unused. Although only one measure of quality, you can check at home whether your vitamins are breaking apart properly with a test similar to what we do in the lab. Place the pill in a cup of water heated to body temperature (about 99 degrees) and stir it for about 30 minutes while keeping the water warm. During that time, the pill should completely break apart, with its contents either turning to a powder or dissolving in the water. Please note that this test is not meant to work for chewable, enteric-coated or timed-release pills.
Tip 2: Look for third-party certification.
Look for certification seals on supplements, such as ConsumerLab’s Approved Quality Seal or the United States Pharmacopeia (USP) seal. These seals ensure that the products you’re buying have passed important tests for quality and contain their key ingredients. ConsumerLab.com provides this certification testing in addition to the reviews of products it selects for testing. In the certification program, companies pay a fee for the testing. ConsumerLab.com does not accept product samples and purchases all supplements on the market, as a consumer would. If a company’s product passes all of our certification tests, it may carry the ConsumerLab.com quality seal for a limited amount of time.
Tip 3: Be wary of “proprietary” formulas or blends.
These are “wiggle words” which allow companies to put in ingredients without promising how much there is of each. If an ingredient is important to you, be sure it and its amount are separately listed.
Tip 4: Know your needs – labels can mislead!
The Supplement Facts panel, typically on the back label of a vitamin bottle, lists the amounts of vitamins and essential minerals per serving. It also shows the percent of the Daily Value (DV) for each nutrient is provided. Unfortunately (and incredibly!), the amounts on which the DV numbers are based have not been updated by the FDA since 1968. The best guidelines for nutrient intake are the newer Recommended Daily Allowances (RDAs) which are not listed on supplement labels. The RDAs often call for different amounts than the Daily Values. For instance, when a label lists 100% DV of vitamin A, this is actually much more than you need. On the other hand, if you see 100% DV for vitamin C and vitamin D, these are actually less than the currently RDAs. Figure out what you really need based on your age, gender, diet, and general health and make sure a supplement provides what you want and not too much (i.e., above the upper limit) of any vitamin or mineral. You can check up-to-date Recommended Daily Allowances and upper limits of vitamins and minerals at ConsumerLab.com/RDAs.