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Supplement Safety

The FDA does regulate dietary supplements; however, it treats them like foods rather than medications.

Unlike drug manufacturers, the makers of supplements don’t have to prove their products are safe or effective before selling them on the market. Instead, the FDA can force a supplement to be removed from the market only if it proves that the supplement is unsafe. That’s an important point to keep in mind. A supplement could be on the market for years before enough people had adverse health effects to prove it’s unsafe. However, there are some efforts in the works to bring supplement manufacturers up to certain standards (called GMP) that are similar to those for pharmaceutical makers. In addition, manufacturers are required to list contact information on the bottle in case there is an adverse effect. These effects are being collected through the FDA Medwatch system in the hopes of more quickly and efficiently finding suspect products and removing them from the public.

“You’ve got to be careful because some supplements can cause a response, some cause no response, and some can cause an adverse response,” notes Gail Cresci, RD, assistant professor of surgery and director of surgical nutrition at the Medical College of Georgia.

The bottom line: Do your research and exercise caution. Here are two more important safety tips:

  • If you eat a balanced diet rich in whole grains, fruits, and vegetables, look for a multivitamin with no more than 100% of the daily value of most vitamins and minerals.
  • Although vitamins are essential to our bodies, in high doses some vitamins can disrupt biochemical pathways, says Cresci. Avoiding high doses is especially important with the fat-soluble vitamins A, D, E, and K because these vitamins build up in your body and can become toxic. (Water-soluble vitamins are excreted in urine if you take more than your body needs.)

Who Should Avoid Supplements and Vitamins?

Supplements are not recommended for people with certain health conditions. Also, some supplements can interact with medications. Always talk with your doctor before adding vitamins or supplements to your diet. People who should avoid certain supplements include:

  • Pregnant or breastfeeding women, because some kinds of supplements can be dangerous to the baby.  A daily prenatal vitamin supplement is perfectly suited to pregnant and lactating women. 
  • Those taking certain medications, including heart medications, diuretics, blood thinners, aspirin, immune-suppressing medications, and steroid medications. All drugs have the potential to interact with dietary supplements, but interactions with these drugs can lead to potential problems that are particularly severe.
  • People who are going to have surgery, because some supplements may lead to bleeding and other dangerous complications.
  • Those being treated for or with a history of cancer, because some supplements could encourage the growth of cancer cells.

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