The Disadvantages of Food Supplements

by August McLaughlin

About August McLaughlin

August McLaughlin is a certified nutritionist and health writer with more than nine years of professional experience. Her work has been featured in various magazines such as "Healthy Aging," "CitySmart," "IAmThatGirl" and "ULM." She holds specializations in eating disorders, healthy weight management and sports nutrition. She is currently completing her second cookbook and Weight Limit—a series of body image/nutrition-related PSAs.


Enter almost any grocery, health food or convenience store and you're likely to find assorted food supplements, also called dietary or nutrition supplements. While supplement sales reached $23.7 billion in the United States in 2007, according to an American Dietetic Association report, many Americans lack knowledge regarding product safety or proper use. A healthy diet is the optimum way to meet your nutritional needs, if you're able. To determine whether supplements can benefit your health, talk to your doctor.

Less Healthy Than Food

Dietary supplements may provide benefits if you have particular medical conditions or difficulty adhering to a healthy diet. Even so, supplements cannot provide all of the benefits and nutrients derived from whole foods. Potent nutrients known as phytochemicals, for example, occur naturally in fruits and vegetables, but are not present in synthetic vitamin supplements. Whole foods also provide unique combinations of nutrients and, in many cases, fiber -- an undigestible form of carbohydrate that supports digestive function and heart health. Supplements that provide vitamin C, lycopene or other antioxidants, do not provide fiber. While B-complex supplements provide many nutrients present in whole grains and legumes, they do not provide valuable amounts of protein and fiber present in these foods.

Side Effects

Food supplements can also pose adverse side effects. Consuming excessive amounts of vitamin A in supplement form, for example, may cause liver damage, reduced bone strength, headaches and birth defects, according to the Office of Dietary Supplements. If you take high doses of zinc, you may experience nausea, vomiting and organ damage. Garlic supplements may cause diarrhea, bleeding, nausea and allergic reactions. Taking a combination of dietary supplements and replacing medications with supplements increases your risk for side effects significantly.

Drug Interactions

Dietary supplements may interact with prescription medications and make it more difficult to manage medical conditions. If you take a blood-thinning medication, for example, vitamin K supplements may reduce its effectiveness and increase your risk for blood clots, according to the Office of Dietary Supplements. Vitamin supplements, such as vitamins E and C, may reduce the effectiveness of cancer chemotherapy medications. For these reasons, discussing use of dietary supplements with your doctor is particularly important if you take medications of any kind.

Unknown Risks

Dietary supplements are not held to the same safety and effectiveness regulations as are medications. The manufacturers are responsible for ensuring each supplement's safety before it is available to consumers, according to the Food and Drug Administration. The FDA provides consumer protection after receiving reports of harmful supplements. Thus, you may experience unexpected, unknown side effects, particularly if the supplement contains questionable ingredients, was mis-marketed or is new to the market. Checking FDA alerts and advisories regarding supplements can help you make wiser choices. Avoid supplements that make unrealistic claims or contain mega-doses of particular nutrients for heightened safety.

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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or