For good health, it is important that you eat a balanced and varied diet. Follow carefully any diet or weight loss program your health care professional may recommend.

 For your specific dietary vitamin and/or mineral needs, ask your health care professional for a list of appropriate foods. If you think that you are not getting enough vitamins and/or minerals in your diet, you may choose to take a dietary supplement.

 
Choosing and using supplements 
 

Supplements, as the term suggests, can complement your regular diet, but they aren't food substitutes. They can't replace the hundreds of nutrients found in whole foods. But if you do decide to take a vitamin or mineral supplement, consider these factors:

 

Check the supplement label. Read labels carefully. Product labels can tell you what the active ingredient or ingredients are, which nutrients are included, the serving size — for example, capsule, packet or teaspoonful — and the amount of nutrients in each serving.

 

The label also provides directions for safe use and tips for storage along with the name and address of the manufacturer, packer or distributor where you can write if you need more information on a particular product.

Avoid supplements that provide "megadoses." In general, choose a multivitamin-mineral supplement that provides about 100 Percent Daily Value (%DV) of all the vitamins and minerals instead of one that supplies, for example, 500%DV of one vitamin and only 20%DV of another. The exception to this is calcium. You may notice that calcium-containing supplements don't provide 100%DV. If they did, the tablets would be too large to swallow. Most cases of nutrient toxicity stem from high-dose supplements.

 

Percent Daily Value (%DV): What does it mean?  

 

Look for “USP” on the label.

This ensures that the supplement meets the standards for strength, purity, disintegration and dissolution established by the testing organization, U.S. Pharmacopeia (USP).

Beware of gimmicks. Synthetic vitamins are usually the same as so-called "natural" vitamins, but "natural" vitamins usually cost more. And don't give in to the temptation of added herbs, enzymes or amino acids — they add mostly cost.

Look for expiration dates. Supplements can lose potency over time, especially in hot and humid climates. If your dietary supplements have expired, discard them. If a supplement doesn't have an expiration date, don't buy it. 

Store all vitamin and mineral supplements safely.

 Store supplements in a dry, cool place. Avoid hot, humid storage locations, such as the bathroom. Also, store supplements out of sight and away from children. Put supplements in a locked cabinet or other secure location. Don't leave them on the counter or rely on child-resistant packaging. Be especially careful with any dieatary supplements containing iron. Iron overdose is a leading cause of poisoning deaths among children.
Play it safe. Before taking anything other than a standard multivitamin-mineral supplement of 100%DV or less, check with your doctor, pharmacist or a registered dietitian. High doses of some vitamins or minerals may cause health problems.

For example:

high doses of vitamin B-3 (niacin) can result in or worsen liver problems, and too much vitamin A over time may cause liver problems or weaken bones in women. In addition, supplements may interfere with your medications. For instance, vitamin E isn't recommended if you're taking blood-thinning medications (anticoagulants) because it can complicate the proper control of blood thinning. If you're already taking an individual vitamin or mineral supplement and haven't told your doctor, discuss it at your next checkup.

 

 Although certain medicines or dietary supplements should not be used together at all, in other cases they may be used together even if an interaction might occur. In these cases, your health care professional may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other dietary supplement or any prescription or non-prescription (over-the-counter [OTC]) medicines.

 

Before Using Dietary Supplements

If you are taking a dietary supplement without a prescription, carefully read and follow any precautions on the label. 

 

Allergies

Tell your health care professional if you have ever had any unusual or allergic reaction to manganese. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

 

Pregnancy

It is especially important that you are receiving enough vitamins and minerals when you become pregnant and that you continue to receive the right amount of vitamins and minerals throughout your pregnancy. The healthy growth and development of the fetus depend on a steady supply of nutrients from the mother. However, taking large amounts of a dietary supplement in pregnancy may be harmful to the mother and/or fetus and should be avoided.

 

Breast-feeding

It is important that you receive the right amounts of vitamins and minerals so that your baby will also get the vitamins and minerals needed to grow properly. However, taking large amounts of a dietary supplement while breast-feeding may be harmful to the mother and/or baby and should be avoided.

 

 

Recommended Dietary Allowances (RDAs) are the amount of vitamins and minerals needed to provide for adequate nutrition in most healthy persons. RDAs for a given nutrient may vary depending on a person's age, sex, and physical condition (e.g., pregnancy).

 

Daily Values (DVs) are used on food and dietary supplement labels to indicate the percent of the recommended daily amount of each nutrient that a serving provides. DV replaces the previous designation of United States Recommended Daily Allowances

 

(USRDAs).

For Canada

Recommended Nutrient Intakes (RNIs) are used to determine the amounts of vitamins, minerals, and protein needed to provide adequate nutrition and lessen the risk of chronic disease.