Benefits of Dietary Supplement

A dietary supplement is intended to provide nutrients that may otherwise not be consumed in sufficient quantities.

Supplements as generally understood include vitamins, minerals, fiber, fatty acids, or amino acids, among other substances. U.S. authorities define dietary supplements as foods, while elsewhere they may be classified as drugs or other products.
There are more than 50,000 dietary supplements available. More than half of the U.S. adult population (53% - 55%) consume dietary supplements with most common ones being multivitamins.
These products are not intended to prevent or treat any disease and in some circumstances are dangerous, according to the U.S. National Institutes of Health. For those who fail to consume a balanced diet, the agency says that certain supplements "may have value."
Most supplements should be avoided, and usually people should not eat micronutrients except people with clearly shown deficiency. Those people should first consult a doctor. An exception is vitamin D, which is recommended in Nordic countries due to weak sunlight.
According to the United States Food and Drug Administration (FDA), dietary supplements are products which are not pharmaceutical drugs, food additives like spices or preservatives, or conventional food, and which also meet any of these criteria:

1. The product is intended to supplement a person's diet, despite it not being usable as a meal replacement.
2. The product is or contains a vitamin, dietary element, herb used for herbalism or botanical used as a medicinal plant, amino acid, any substance which contributes to other food eaten, or any concentrate, metabolite, ingredient, extract, or combination of these things.
3. The product is labeled as a dietary supplement.

In the United States, the FDA has different monitoring procedures for substances depending on whether they are presented as drugs, food additives, food, or dietary supplements. Dietary supplements are eaten or taken by mouth, and are regulated in United States law as a type of food rather than a type of drug. Like food and unlike drugs, no government approval is required to make or sell dietary supplements; the manufacturer checks the safety of dietary supplements but the government does not; and rather than requiring risk–benefit analysis to prove that the product can be sold like a drug, risk–benefit analysis is only used to petition that food or a dietary supplement is unsafe and should be removed from market.

Medical uses

The intended use of dietary supplements is to ensure that a person gets enough essential nutrients.
Dietary supplements should not be used to treat any disease or as preventive healthcare. An exception to this recommendation is the appropriate use of vitamins.
Dietary supplements are unnecessary if one eats a balanced diet.
Supplements may create harm in several ways, including over-consumption, particularly of minerals and fat-soluble vitamins which can build up in the body. The products may also cause harm related to their rapid absorption in a short period of time, quality issues such as contamination, or by adverse interactions with other foods and medications.

Types of dietary supplements

There are many types of dietary supplements.

Vitamins

Vitamin is an organic compound required by an organism as a vital nutrient in limited amounts. An organic chemical compound (or related set of compounds) is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on the circumstances and on the particular organism. For example, ascorbic acid (vitamin C) is a vitamin for humans, but not for most other animals. Supplementation is important for the treatment of certain health problems but there is little evidence of benefit when used by those who are otherwise healthy.

Dietary element

Dietary elements, commonly called "dietary minerals" or "minerals", are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. The term "dietary mineral" is archaic, as the substances it refers are chemical elements rather than actual minerals.

Herbal medicine

Herbal medicine is the use of plants for medicinal purposes. Plants have been the basis for medical treatments through much of human history, and such traditional medicine is still widely practiced today. Modern medicine recognizes herbalism as a form of alternative medicine, as the practice of herbalism is not strictly based on evidence gathered using the scientific method. Modern medicine, does, however, make use of many plant-derived compounds as the basis for evidence-tested pharmaceutical drugs, and phytotherapy works to apply modern standards of effectiveness testing to herbs and medicines that are derived from natural sources. The scope of herbal medicine is sometimes extended to include fungal and bee products, as well as minerals, shells and certain animal parts.

Amino acids and proteins

Amino acids are biologically important organic compounds composed of amine (-NH₂) and carboxylic acid (-COOH) functional groups, along with a side-chain specific to each amino acid. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in the side-chains of certain amino acids.
Amino acids can be divided into three categories: essential amino acids, non-essential amino acids, and conditional amino acids. Essential amino acids cannot be made by the body, and must be supplied by food. Non-essential amino acids are made by the body from essential amino acids or in the normal breakdown of proteins. Conditional amino acids are usually not essential, except in times of illness, stress, or for someone challenged with a lifelong medical condition.

Essential fatty acids

Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them. The term "essential fatty acid" refers to fatty acids required for biological processes but does not include the fats that only act as fuel.

Bodybuilding supplements

Bodybuilding supplements are dietary supplements commonly used by those involved in bodybuilding and athletics. Bodybuilding supplements may be used to replace meals, enhance weight gain, promote weight loss or improve athletic performance. Among the most widely used are vitamin supplements, protein drinks, branched-chain amino acids (BCAA), glutamine, essential fatty acids, meal replacement products, creatine, weight loss products and testosterone boosters. Supplements are sold either as single ingredient preparations or in the form of "stacks" - proprietary blends of various supplements marketed as offering synergistic advantages. While many bodybuilding supplements are also consumed by the general public their salience and frequency of use may differ when used specifically by bodybuilders.

According to University of Helsinki food safety professor Marina Heinonen, more than 90% of dietary supplement health claims are incorrect.

Adverse effects 

The number of incidents of liver damage from dietary supplements has tripled in a decade. Most of the supplements were bodybuilding supplements. Some of the patients require liver transplants and some die. In third of the supplements involved contained unlisted steroids.