Dietary Supplements

By Ellen Daley, MS, RD, CDE

Dietary supplements make promises for “fat burners”, “metabolic booster” , and “rapid muscle builder”. It is easy to see why we spend 30 billion dollars a year on dietary supplements. Can we believe these claims? Do we need them?

Supplements include vitamins, minerals, herbs, amino acids and enzymes. The Food and Drug Administration (FDA) inspects food and prescription drugs, but they do not inspect supplements for purity, safety or effectiveness. A recent study looked at a dietary supplement advertised to reduce cholesterol. The study reviewed 28 different brands and found two of the brands had none of the advertised ingredient, six had levels that were too high, and the rest had a wide range of the ingredient. This illustrates one problem with supplements; you often do not know what you are getting in that bottle. Athletes need to be especially careful about dietary supplements because they may include banned substances that could result in elimination from competition.

Supplements should not replace a healthy diet. A balanced diet can meet your energy, protein, vitamin and mineral needs. However, there are times a supplement may be helpful, for example, a student with a diagnosed medical issue, an athlete with very high calorie needs, a person with a food allergy that leads to eliminating a food group or a person with a poor diet.  

Should you consider a multivitamin to help meet your needs? Research on the benefits of taking a multivitamin have shown mixed results. You can get all the vitamins and minerals you need from a balanced diet, but if you think your diet is lacking and want to take a multivitamin, choose one with no more than 100% of the Daily Value (DV) for each nutrient. It is best to take the vitamin with food for better absorption. Look for the USP (US Pharmacopeia) logo. USP is a non-profit organization of scientists that verify the product contains the listed ingredients and in the amounts listed on the label. They also verify that no dangerous substances are contaminating the product.

Supplementing with individual vitamins and minerals, especially when taking more than 100% DV, puts you at risk for toxicity. Some supplements, like iron and Vitamin A, can cause toxic effects when excess amounts are taken and can lead to upset stomach, birth defects, liver toxicity just to name a few. There are times when individual supplements in larger dosages may be prescribed by your doctor, for example an iron supplement for a woman with iron deficiency anemia or folic acid for a woman planning to get pregnant or Vitamin D for a student who is deficient.   If you have questions about taking individual supplements, talk to your health care provider or pharmacist.

You can get all your vitamins and minerals from food and you do not have to worry about getting toxic levels from food. See the chart below for a list of the best food sources of vitamins and minerals.

Have questions or want to learn more about supplements and your diet? Set up an appointment with Ellen Daley, Nutrition Specialist at Health Services.