When deciding whether or not to take a dietary supplement, consider the ABCs, as in Always Be Careful, advices Dr. Jo Ann Carson, associate professor of clinical nutrition.

Speaking at a health and fitness series sponsored by the Bryan William, M.D., student center, Dr. Carson’s top 10 things to know about dietary supplement include: Dietary supplements are not regulated like medications or even foods.

• Dietary Reference Intakes (DRIs) are helpful numbers to use.
• Many individuals do not get the recommended amount of calcium or iron.
• There are contrindicators for some supplements/herbs, such as St. John’s wort in HIV patients on protease inhibitors.
• The internet contains a wealth of sound and misleading information on dietary supplements
• An overall healthy, varied diet is an important foundation for healthy living; supplements cannot adequately makeup for a poor diet.
• Too much of one nutrient can interfere with other nutrient absorption, use and/or function.
• Some nutrients are better absorbed from foods.
• Watch out for vitamins A and D and minerals, which can be toxic at high doses.
• Know the ABCs of dietary supplement – Always Be Careful. 

             “Individual should not overly rely on supplements,” Dr. Carson said. “The biggest harm that I see in taking a supplement is that people might feel ensured that they will be what they need in the supplement and they may not work as hard to eat a variety of food.”

             In some cases, dietary supplements are necessary, Dr. Carson added.

             For example, calcium supplements are beneficial particularly in women who, during menopause, lose more calcium in their bone. And for the individuals who do not get the recommended dietary intake of calcium – 1,000 milligrams for individuals 19 t0 50 and 1,300 for those 50 and over – a supplement is beneficial.

             An 8-ounce glass of milk, one of the best sources of calcium, is not equivalent to 300 mg of calcium.

             “If you know that you don’t take in the appropriate amount of dairy foods, then itt is a good idea to take a calcium supplement,” Dr. Cason said.

             Iron is an essential mineral that is lacking in the diets of many pre menopausal women. The National Academy of Sciences’ Recommended Dietary Allowance (RDA) for iron for females between ages 11 and 50 is 15 mg a day and for pregnant women, 30mg. The RDA for men and women over 50 is 10mg of iron.

             A wealth of information about dietary supplements can be found on the Internet, but Dr. Carson advices against seeking information from a site that is selling the product.

             The dietary Reference Intake (DRI) guide, set by the Food and Nutrition Board of the Institute of Medicine – National Academy of Sciences, is an important reference for individuals, Dr. Carson said.

             The DRIs are a set of four reference values: Estimated Average Requirement (EAR), Recommended Dietary Allowances (RDA), Adequate Intake (AI) and Tolerable Upper Intake Levels (UL).

             Taking dose of some supplements that exceed the RDA may or may not do harm to the body.          

             For example, the RDA for vitamin E for adults is 15mg, but the UL is 1,000mg.          

             “Large clinical trials have shown that there were not any significant problems with people taking vitamin E in excess (1,000mg), and it appears to be safe,” Dr. Carson said.

             In contrast, too much vitamin A and D can be harmful.

             In pregnant women, vitamin A in excess may result in birth defects.           

             Exceeding the recommended dosage of vitamin A also may increase the risk of liver abnormalities and may reduce bone mineral density, which could result in osteoporosis.           

             Taking too much vitamin D poses the risk of several toxic effects, including nausea, headache, excessive urination, high blood pressure, deposits of calcium in soft tissues and kidney damage.          

             “Taking large doses of one dietary supplement, particularly minerals, may interfere with the absorption or utilization of other nutrients. So it’s best not to take a large does of any one supplement unless its’ for a specific situation,” Dr. Carson said.

             While dietary supplement may not be beneficial if an individual is not getting adequate nutrients and minerals, some nutrients are absorbed better from food, Dr. Carson said. These include calcium and Iron.

             Folate, however, is better absorbed from a supplement.

             When selecting a multivitamin, Dr. Carson said, the label should indicate 100 percent of most nutrients and minerals.