Dietary Supplements: More is Not Always Better

by National Institute on Aging

Bill's retired and lives alone. Often he's just not hungry or is too tired to fix a whole meal. Does he need a multi-vitamin or one of those dietary supplements he sees in ads everywhere? He wonders if they work - will one help his arthritis, or another give him more energy? And, are they safe?

"Dietary supplements" used to make you think only of vitamins and minerals. But, today this big business makes and sells many different types of dietary supplements that have vitamins, minerals, fiber, amino acids, herbs, or hormones in them. Supplements come in the form of pills, capsules, powders, gel tabs, extracts, or liquids. Sometimes you find them added to drinks or energy bars. They might be used to add nutrients to your diet or to prevent health problems. You don't even need a prescription from your doctor to buy dietary supplements.

Do I Need a Dietary Supplement?

Ads for supplements seem to promise to make you feel better, keep you from getting sick, or even help you live longer. Often there is little, if any, scientific support for these claims. In fact, some supplements can hurt you. Others are a waste of money because they don't give you any health benefits.

So, should you take a supplement? You might want to talk to your doctor or a registered dietitian to answer that question. A friend or neighbor, or someone on a commercial shouldn't be suggesting a supplement for you.

Are These Supplements Safe?

Are you thinking about using dietary supplements? Remember that these "over-the-counter" substances are not like the penicillin or blood pressure medicine your doctor might prescribe for you. The U.S. Food and Drug Administration (FDA) has to check prescription drugs to make sure they are safe and do what they promise before they are sold. The same is true for "over-the-counter drugs" like cold and pain medicines. It is not the FDA's job to check dietary supplements in the same way. That means they are not reviewed by the FDA before being sold, but it is the FDA's job to take action against unsafe products on the market. Only if enough people report problems with a dietary supplement, can the FDA study these possible problems and take action.

Besides the FDA, many federal government agencies and private groups are interested in dietary supplements. The National Institutes of Health (NIH) is the federal focal point for medical research in the United States. NIH supports research studies looking at the safety and helpfulness of some of the ingredients found in many supplements.

Business and consumer groups are also interested in dietary supplements. So are private professional groups such as the National Academy of Sciences (NAS). The NAS develops guidelines saying how much of each vitamin and mineral people need.

What About Vitamins and Minerals?

Vitamins and minerals are nutrients found naturally in food. We need them to stay healthy. The benefits and side effects of many vitamins and minerals have been studied.The best way to get vitamins and minerals is through the food you eat, not any supplements you might take. Try to eat the number of servings of food recommended by the U.S. Department of Agriculture's Food Guide Pyramid each day (see chart). Pick foods that are lower in fat and added sugars. If you can't eat enough, then ask your doctor if you should be taking a multivitamin and mineral supplement. And remember: The supplement doesn't need to be a "senior" formula. It shouldn't have large or "mega-doses" of vitamins and minerals. Generally store or generic brands are fine.

How much should you take? The NAS has developed recommendations for vitamins and minerals. Check the label on your supplement bottle. It shows the level of vitamins and minerals in a serving compared with the suggested daily intake.

How Many Servings Do You Need?

• Bread, cereal, rice, and pasta - 6 to 11 servings
• BVegetables - 3 to 5 servings
• BFruits - 2 to 4 servings
• BMilk, yogurt, and cheese - 2 to 3 servings
• BMeat, poultry, fish, dry beans, eggs, and nuts -2 to 3 servings
• BFats, oils, and sweets - use sparingly

For example, a vitamin A intake of 100% DV (Daily Value) means the supplement is giving you the full amount of vitamin A you need each day. This is in addition to what you are getting from your food.

Some people might think that if a little is good, a lot must be better. But, that doesn't necessarily apply to vitamins and minerals. Depending on the supplement, your age, and your health, taking more than 100% DV could be harmful to your health. Also, if your body cannot use the entire supplement you take, you've wasted money. Finally, large doses of some vitamins and minerals can also keep your prescription medications from working as they should.

Anything Special For People Over 50?

Even if you eat a good variety of foods, if you are over 50, you might need certain supplements. Talk to your doctor or a registered dietitian. Depending on your needs, he or she might suggest you get the following amounts from food and, if needed, supplements:

Vitamin B12 - 2.4 mcg (micrograms) of B12 each day. Some foods, such as cereals, are fortified with this vitamin. But, up to one-third of older people can no longer absorb natural vitamin B12 from their food. They need this vitamin to keep their blood and nerves healthy.

About the Author

www.nia.nih.gov
NIA, one of the 27 Institutes and Centers of NIH, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. In 1974, Congress granted authority to form NIA to provide leadership in aging research, training, health information dissemination, and other programs relevant to aging and older people.