Dietary supplements are foods. They are intended to supplement a normal diet. Dietary supplements may contain a broad spectrum of nutrients or other substances with a specific nutritional or physiological effect. They may be, for instance, vitamins, minerals, trace elements, amino acids, fibre, plants or herbal extracts which are either added individually or as a combination in concentrated form. Dietary supplements are sold in a dosage form, for instance as tablets, capsules, coated tablets, powders or liquids for intake in small, measured amounts. In contrast to conventional foods, dietary supplements may come with a recommended intake along with other specific information for consumers, e.g. that they should be stored out of the reach of small children.

According to the Dietary Supplement Health and Education Act, or DSHEA, a dietary supplement is any product that contains one or more dietary ingredients such as a vitamin, mineral, herb or other botanical, amino acid or other ingredient used to supplement the diet. Dietary supplements are not food additives (such as saccharin) or drugs.

Supplements provide vitamins and minerals normally found in food. Some medications increase the need for specific nutrients, particularly Vitamin C, folic acid or B Complex and liver supporting herbs such as Milk Thistle. There are occasions, however, when supplements interfere with some medications e.g. taking calcium, magnesium, iron or other minerals with the antibiotic tetracycline. You should also avoid nutrients or herbs that have blood thinning effects such as Vitamin E, Omega 3, Co Enzyme Q10, Horse chestnut, Sweet clover (mellilotus), Ginkgo biloba and high dose Garlic or Ginger, if taking anticoagulants such as warfarin.

Adverse drug-nutrient interactions are actually quite rare and the over-whelming majority of interactions are positive. Drugs like sulfasalazine used to treat colitis or rheumatoid arthritis deplete folic acid. Aspirin depletes Vitamin C and folic acid, diuretics deplete minerals and the contraceptive pill depletes the B Complex vitamins and a range of minerals. The list is extensive so finding a doctor who can give you advice on both conventional and nutritional medicine, or seeing a naturopath or checking with your pharmacist that what you are taking won’t interfere with your medication is advisable. If none of these options are helpful contact the company whose products you are taking and request the appropriate information.

Many terms are used when referring to either the amount of a particular nutrient (such as calcium or vitamin D) you should get or the amount in a food or dietary supplement. The two most common are the Recommended Dietary Allowance (RDA) and the Daily Value (DV). These terms can be confusing.

RDAs are recommended daily intakes of a nutrient for healthy people. They tell you how much of that nutrient you should get on average each day. RDAs are developed by the Food and Nutrition Board at the Institute of Medicine of the National Academies. They vary by age, gender and whether a woman is pregnant or breastfeeding; so there are many different RDAs for each nutrient.

DVs, established by the U.S. Food and Drug Administration (FDA), are used on food and dietary supplement labels. For each nutrient, there is one DV for all people ages 4 years and older. Therefore, DVs aren’t recommended intakes, but suggest how much of a nutrient a serving of the food or supplement provides in the context of a total daily diet. DVs often match or exceed the RDAs for most people, but not in all cases.

DVs are presented on food and supplement labels as a percentage. They help you compare one product with another. As an example, the %DV for calcium on a food label might say 20%. This means it has 200 mg (milligrams) of calcium in one serving because the DV for calcium is 1,000 mg/day. If another food has 40% of the DV for calcium, it’s easy to see that it provides much more calcium than the first food.

Yes. Dietary supplements are regulated, although not in the way prescription or over-the-counter drugs are. Because dietary supplements are foods and not drugs, the FDA has the power to ensure that products on the market are both safe and accurately labeled. Before a product can be sold, a manufacturer must first notify the FDA of all intended label claims and ensure that they can be substantiated.

Unfortunately, some journalists have incorrectly reported that the supplement industry is unregulated, which is absolutely false. All supplements, including vitamins, minerals, herbs and specialty products must conform to federal regulations that control manufacturing, labeling and advertising practices.

Manufacturers are required to follow “good manufacturing practices” (GMPs), which means their supplements have to meet certain quality standards. However, it has been found that some products may contain more or less of the ingredient than is stated on the label. Or, in some cases they may contain ingredients not listed on the label, including prescription drugs.

To be sure you’re getting a good-quality product, look for a seal of approval from an organization that tests supplements. Products that carry these organizations’ seal must be manufactured properly, contain the ingredients listed on the label, and not include any harmful contaminants.

You can also call the product’s manufacturer to find out what research they’ve done to confirm the supplement’s benefits, what production standards they use, and what side effects have been reported from their product. Find out if the supplement hasn’t been recalled, by checking the FDA’s web site.

The length of time you will require dietary supplementation depends on the reason you are taking them, e.g. if your diet is deficient in iron, you will require iron supplementation until your blood tests are normal. After which time if you have increased your intake of iron containing foods, ongoing supplementation won’t be necessary.

However, if you are on medication that effects nutrient levels or you have a specific health problem, ongoing supplementation maybe beneficial. If you have any doubts about what you are taking, we suggest you consult a naturopath or contact the company whose products you are taking.