Family Health Guide

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Vitamins and Supplements: Supplement Safety Rules

Always talk with your doctor before taking any supplements. Here are four more important points to know.

  • Stay within the limts. Unless specifically instructed by your doctor, don’t take supplements that contain more than the DRI (Dietary Reference Intake) for any single nutrient.  Some nutrients have toxic effects when taken in high doses, and some present risks to your baby, should you become pregnant while taking high doses. “When it comes to supplements, some is good but more is not necessarily better, especially during pregnancy,” says Laura Riley, M.D., medical director of labor and delivery at Massachusetts General Hospital and author of the book, You and Your Baby: Your Ultimate Week-By-Week Pregnancy Guide.  “Taking too much of certain vitamins can be dangerous. For example, high levels of vitamin A during pregnancy can lead to birth defects. It’s always best to stay within recommended amounts.”
  • Avoid herbal supplements during your childbearing years, unless specifically instructed to take them by your physician.  Some herbal supplements have been shown to be dangerous during pregnancy, and many simply haven’t been proven safe so are not recommended.  “Just because a label says something is ‘natural’ doesn’t mean it is safe,” says Melinda Johnson, RD, ADA spokesperson and lecturer at Arizona State University.  “Herbal supplements act more like drugs in the body and just as you wouldn’t take drugs while pregnant, nursing, or trying to become pregnant, you should stay away from herbal supplements, too.”

  • Watch fortified foods.  “Energy bars, vitamin drinks, and other heavily fortified foods act more like supplement pills than food,” says Johnson. “When you eat a lot of fortified foods and you consume dietary supplements, you might get mega doses of certain nutrients, which could be dangerous.  Base your diet on unprocessed foods such as whole grains, fresh fruits and vegetables.” 

  • Choose high quality supplements recommended by your physician, to ensure that they’re safe, and that they contain only what they claim on the label. (Some supplements have been found to contain unlisted ingredients or contaminants.)  Two organizations that test the safety and integrity of supplements and make sure they meet certain standards and criteria are the United States Pharmacopeia (USP) and NSF International (NSF).  Look for the USP and/or NSF mark on the label.


Nutrients You May Be Lacking

Some vitamins and minerals are simply harder to get exclusively through food. Here are the most common deficiencies in women of childbearing age. In addition to these five nutrients, if you don’t consume meat in your diet – and especially if you are a vegan and consume no animal products at all – you may be at risk for deficiencies of zinc and vitamin B-12, since animal products are the main sources for these nutrients. Check with your doctor about whether you should have your blood levels of these nutrients checked.