Dietary Supplements
Edited by Andy Ross
A dietary supplement or nutritional supplement is a preparation intended to
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. Some countries define dietary supplements as foods,
while in others they are defined as drugs or natural health products.
Supplements containing vitamins or dietary minerals are included as a
category of food in the Codex Alimentarius, a collection of internationally
recognized standards, codes of practice, guidelines, and other
recommendations relating to foods, food production, and food safety. The
Codex Alimentarius Commission is sponsored by the UN Food and Agriculture
Organization (FAO) and the World Health Organization (WHO).
European Union
The EU Food Supplements Directive of 2002 requires that supplements be
demonstrated to be safe, both in dosages and in purity. Only those
supplements that have been proven to be safe may be sold in the bloc without
prescription. As a category of food, food supplements cannot be labeled with
drug claims but can bear health claims and nutrition claims.
The
dietary supplements industry in the UK opposed the directive. A large number
of consumers throughout Europe and various doctors and scientists signed
petitions against what they saw as an unjustified restriction of consumer
choice.
The European Court decided that the measures in question were
necessary and appropriate. But they acknowledged the concerns, stating that
there must be clear procedures to allow substances to be added to the
permitted list based on scientific evidence. They also allowed that any
refusal to add a product to the list is open to challenge in the courts.
United States
In the United States, a dietary supplement is defined under the Dietary
Supplement Health and Education Act of 1994 (DSHEA) as a product that is
intended to supplement the diet and contains any of the following dietary
ingredients: a vitamin; a mineral; an herb; an amino acid; a concentrate,
metabolite, constituent, extract, or combination of them; or a substance
used historically to supplement the human diet.
According to the act,
a dietary supplement must be intended for ingestion in pill, capsule,
tablet, powder or liquid form; not represented for use as a conventional
food or as the sole item of a meal or diet; and labeled as a dietary
supplement.
The Food and Drug Administration (FDA) regulates dietary
supplements as a category of foods and does not need to approve them before
they can enter the market. But manufacturers and distributors who wish to
market dietary supplements that contain a new dietary ingredient must notify
the FDA in advance with information indicating the ingredient is safe for
the agency to review.
The FDA has implemented a current good
manufacturing practices (cGMP) policy to ensure dietary supplements are
produced in a quality manner, do not contain contaminants or impurities, and
are accurately labeled. Based on audits completed in 2011 and 2012, the FDA
estimated that nearly 70% of dietary supplement manufacturers are currently
not compliant with cGMP.
The Dietary Supplement and
Nonprescription Drug Consumer Protection Act of 2006 established
requirements for manufacturers to submit to the FDA reports of serious
adverse events involving their products.
The DSHEA restricted the
ability of the FDA to exert authority over supplements as long as
manufacturers made no claims about their products treating, preventing, or
curing diseases. According to Consumer Reports, the law has left consumers
without protection and assigns to the FDA the burden of proof that a
supplement is unsafe. While pharmaceutical manufacturers must demonstrate
their products are effective as well as being safe, supplement manufacturers
are not required to demonstrate efficacy.
Because of the requirements
put into place by the DSHEA, the FDA must demonstrate that individual
supplements are unsafe using their adverse events reporting system. The FDA
has also lacked the funding to undertake the rigorous tests to meet the
standards for a supplement to be considered hazardous.
The FDA
defines a quality dietary supplement as one that consistently meets the
established specifications for identity, purity, strength, and composition
and has been manufactured, packaged, labeled, and held under conditions to
prevent adulteration. But enforcement is difficult.
Contamination and
false labeling are common. Much of the contamination is due to poor raw
ingredients. Suppliers provide certificates of analysis stating that they
have tested the material. Retesting is not required if the manufacturer has
verified the reliability of the ingredient supplier.
United States
Pharmacopeia (USP) manages the Dietary Supplement Verification Program
(DSVP). Its USP Verified Mark seal indicates that the product has been
tested for integrity, purity, dissolution, and safe manufacturing. The USP
program conducts random off-the-shelf testing and will not certify products
that contain ingredients that it determines have a safety risk.
ConsumerLab.com randomly tests dietary supplements and reports that a
quarter of those it tests have problems. NSF International, HFL Sport
Science, and the Natural Products Association (NPA) also have dietary
supplement certification programs.
A dietary supplement claiming to
cure or treat a disease would be considered an unauthorized new drug and in
violation of the applicable regulations and statutes. Companies that market
dietary supplements are permitted to make broad claims in the marketing
material that the product can support the structure or function of the body.
The FDA must be notified and the claims must be substantiated. Health claims
require approval from FDA.
