A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet.
It must be remembered that whether a molecule has become a drug or a dietary supplement, or perhaps both, depends upon "accidents" of the time, manner, and purpose of its coming into human usage and into the marketplace. A more recent term for supplement ingredients derived from plants is phytopharmaceutical (or phytochemical).
The label of a dietary supplement or food product may contain one of three types of claims: a health claim, nutrient content claim, or structure/function claim. Health claims describe a relationship between a food, food component, or dietary supplement ingredient, and reducing risk of a disease or health-related condition. Nutrient content claims describe the relative amount of a nutrient or dietary substance in a product. A structure/function claim is a statement describing how a product may affect the organs or systems of the body and it can not mention any specific disease.
If a dietary supplement is labeled for the treatment or prevention of disease, it becomes a drug, and must be proven safe and effective prior to marketing. Dietary supplements are not drugs, and therefore are not subject to the usual FDA drug approval process; however, manufacturers are responsible for the safety of their products. Any new dietary supplement is allowed to enter the market only after a 75-day period during which the FDA has the opportunity to review the manufacturer's data supporting safety of the supplement.
Supplements are not without risks. Some supplements induce harmful side-effects; indeed, many
deaths have been reported, especially from herbs. Another potential problem is that supplements may cause a person to delay taking appropriate action to deal with a treatable condition. For example, trying to lose weight or lower blood cholesterol with supplements that have little or no value may cause people to delay starting treatments that have proven value.
Our results suggest an illusory sense of invulnerability may mediate the connection between use of dietary supplements and poor judgment about health-related behaviors (e.g., the choice of hedonic activities over exercise or buffet-type meals over organic meals). Hence, people who rely on dietary supplements for health protection may pay a hidden price: the curse of licensed self-indulgence.
A recent study reported that dietary supplement use has increased in the United States, with more than half of all adults taking dietary supplements. The most common dietary supplement you might take is a multivitamin. Many believe it may be an "insurance policy" to make sure you're getting all necessary nutrients, but there isn't much evidence a multivitamin will improve your health, and it won't make up for a bad diet.
In fact, 69 percent of U.S. adults take dietary supplements according to a survey commissioned by the Council for Responsible Nutrition (CRN), which is the dietary supplement industry's leading trade association. Consumer usage of dietary supplements is up from 66 percent in 2010, 65 percent in 2009, and 64 percent in 2008. Our fast moving society and demand for quick, cheap, nutritional meals is also boosting the "meal replacement market;" shakes, protein bars and other high calorie, vitamin balance snacks are growing fast as well.
The study looked at more than 38,000 women age 55 and older who participated in the Iowa Women's Health Study since the mid-1980s. The researchers found that when it came to reducing the risk of death, most supplements had no effect on women's health; in fact, women who took certain kinds of dietary supplements -- vitamin B6, folic acid, magnesium, zinc, copper, iron and multivitamins -- faced a slightly higher risk of death than women who did not. Only women who took supplemental calcium showed any reduction in their risk of death.
Robert Post, deputy director of the U.S. Department of Agriculture’s Center for Nutrition Policy and Promotion, says too few Americans are meeting all their nutritional requirements and that dietary supplements, used sensibly, can help fill gaps in our diets. In particular, he notes, the guidelines single out four “nutrients of concern” that most of us need more of to maintain good health: potassium, Vitamin D, calcium and fiber (see chart). But Post, like the guidelines, calls for people to get their fill of those four nutrients from food and to consider supplements only for a handful of dietary deficiencies related to our stage of life and dietary preferences.
Responsible companies follow the Good Manufacturing Practices (GMPs) regulations that became fully effective in 2010. These rules prescribe step-by-step requirements for the manufacturing and testing of dietary supplements--from the raw ingredients coming into a plant to the finished products headed for consumers--and place absolute responsibility on the manufacturers and distributors, including the actions of any testing labs they hire.