What are the risks of taking supplements?
Herbal supplements can interact negatively with prescription medicines. For example, if the kidney or liver is supposed to clear a drug from the body, an herbal supplement may interfere with the body’s natural metabolic process, causing that medicine to stay in the body for a shorter or longer amount of time than it should.
If you’re undergoing surgery, it’s also important to avoid supplements that may increase bleeding risk, such as garlic extract, ginseng extract, bilberry extract and fish oil.
Also, quality of herbal supplements is a concern, more so than with vitamin or mineral supplements. The herbal supplement may not contain the advertised ingredient or in quantities not consistent with what is on the label. Additional concerns include contamination with heavy metals like arsenic, lead or mercury.
If a supplement is prescribed, what should the patient consider when choosing a supplement?
If your doctor prescribes a supplement, make sure you understand why you need to take it, how much (the dose) and for how long. You can look up a supplement online through the National Institutes of Health to learn more about its health benefits and any safety concerns.
Some supplements have claims on the bottle that aren’t consistent with what they can actually do. It’s important to understand why you’re taking a particular supplement, and why you need each of the ingredients in that product.
A study once used DNA Bar Coding analysis of over-the-counter supplements and found incorrect labeling on almost half of those included in the study. One product was labeled as having St. John’s Wort — an herbal product commonly used to treat depression — but the product actually contained senna, which is a non-prescription herbal laxative. It’s important to know what you’re putting into your body, so you don’t accidentally take something that could have an unexpected or negative impact on your health.
Multivitamins have several vitamins and minerals, but they may also have dozens of other ingredients that might have harmful side effects or interactions with your prescribed medications. It’s best to take only the vitamins you need and avoid ingredients that don’t meet your prescribed needs.
Also, be cautious of terms like “proprietary blend.” If a manufacturer isn’t willing to share all of the ingredients on the label, you might not know what’s really in that product.