Multivitamin
Encyclopedia
A multivitamin is a preparation intended to supplement a human diet with vitamin
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound 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...

s, dietary mineral
Dietary mineral
Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. Examples of mineral elements include calcium, magnesium, potassium, sodium, zinc, and iodine...

s, and other nutritional elements. Such preparations are available in the form of tablets, capsules, pastilles, powders, liquids, and injectable formulations. Other than injectable formulations, which are only available and administered under medical supervision, multivitamins are recognized by the Codex Alimentarius Commission (the United Nations
United Nations
The United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...

' authority on food standards) as a category of food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...

. Multivitamin supplements are commonly provided in combination with dietary minerals. A multivitamin/mineral supplement is defined in the United States as a supplement containing 3 or more vitamins and minerals that does not include herb
Herb
Except in botanical usage, an herb is "any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or "a part of such a plant as used in cooking"...

s, hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

s, or drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...

s, where each vitamin and mineral is included at a dose below the tolerable upper level, as determined by the Food and Drug Board, and does not present a risk of adverse health effects.
The terms multivitamin and multimineral are often used interchangeably. There is no scientific definition for either.

History

In the mid-1930s multivitamins became available in pharmacies and grocery stores. In 1934 Nutrilite Company
Nutrilite
Nutrilite is a brand of mineral, vitamin, and dietary supplements created in 1934 by Dr. Carl F. Rehnborg. Nutrilite products are currently manufactured by Access Business Group, a subsidiary of Alticor whose products are sold via the Amway and Amway Global Corporations worldwide...

 introduced the first multivitamin-multimineral tablets. These supplements were made from natural dried and compressed vegetable and fruit concentrates. In the early 1940s other brands started to produce synthetic tablets.

Products and components

Many multivitamins are formulated or labeled to differentiate consumer sectors, such as prenatal, children, mature or 50+, men's, women's, diabetic, or stress. Consumer multivitamin formulas are available as tablets, capsules, bulk powder, or liquid. Most multivitamins are intended to be taken once or twice per day, although some formulations are designed for consumption 3–7 or more times per day.

Compositional variation amongst brands and lines allows substantial consumer choices. Modern multivitamin products roughly classify into RDA
Dietary Reference Intake
The Dietary Reference Intake is a system of nutrition recommendations from the Institute of Medicine of the U.S. National Academy of Sciences. The DRI system is used by both the United States and Canada and is intended for the general public and health professionals...

 (recommended dietary allowance) centric multivitamins with or without iron, RDA centric multivitamin/multimineral formulas with or without iron, higher potency formulas with mostly above RDA components with or without iron, and more specialized formulas by condition, such as for diabetics or by less common components, such as diversified antioxidants, herbal extracts, or premium vitamin and mineral forms. Legally, the United States Food and Drug Administration allows a multivitamin to be called "high potency" if at least two-thirds of its nutrients have at least 100 percent of the DV
Dietary Reference Intake
The Dietary Reference Intake is a system of nutrition recommendations from the Institute of Medicine of the U.S. National Academy of Sciences. The DRI system is used by both the United States and Canada and is intended for the general public and health professionals...

. In practice, "high potency" usually means substantially increased vitamins C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...

 and B, with some other enhanced vitamin and mineral levels, though some minerals may still be much less than DV.

Some components are typically much lower than RDA amounts, often for cost reasons. For example, biotin
Biotin
Biotin, also known as Vitamin H or Coenzyme R, is a water-soluble B-complex vitamin discovered by Bateman in 1916. It is composed of a ureido ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring...

, usually the most expensive vitamin component, at over $4000 per active pound
Pound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...

, is typically added in at only 5%-30% of RDA in many one per day formulations. Biotin is required to be present at 100% of the value of the B-vitamins for them to be absorbed by the body. Any B-vitamins that cannot be absorbed due to a lack of biotin are eliminated by the body. Likewise, boron
Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...

 and magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

 are considered essential for the bioavailability
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...

 and absorption of Vitamin D and calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

. Sometimes low content composition is for population subgroups, where the RDA would be inappropriate. Iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 is needed in larger amounts by menstruating women, but some percentage of HFE variant gene bearing males are at risk for hemochromatosis. Normal dietary intakes also vary by population, indicating different levels of supplementation.

Basic commercial multivitamin supplement products often contain the following ingredients:
vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...

, B1, B2, B3, B6
Vitamin B6
Vitamin B6 is a water-soluble vitamin and is part of the vitamin B complex group. Several forms of the vitamin are known, but pyridoxal phosphate is the active form and is a cofactor in many reactions of amino acid metabolism, including transamination, deamination, and decarboxylation...

, folic acid
Folic acid
Folic acid and folate , as well as pteroyl-L-glutamic acid, pteroyl-L-glutamate, and pteroylmonoglutamic acid are forms of the water-soluble vitamin B9...

 (B9), B12
Vitamin B12
Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...

, B5 (pantothenate), H (biotin
Biotin
Biotin, also known as Vitamin H or Coenzyme R, is a water-soluble B-complex vitamin discovered by Bateman in 1916. It is composed of a ureido ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring...

), A
Vitamin A
Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...

, E
Vitamin E
Vitamin E is used to refer to a group of fat-soluble compounds that include both tocopherols and tocotrienols. There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet. γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings...

, D3, K1, potassium iodide
Potassium iodide
Potassium iodide is an inorganic compound with the chemical formula KI. This white salt is the most commercially significant iodide compound, with approximately 37,000 tons produced in 1985. It is less hygroscopic than sodium iodide, making it easier to work with...

, cupric (sulfate anhydrous, picolinate, sulfate monohydrate, trioxide), selenomethionine
Selenomethionine
Selenomethionine is an amino acid containing selenium. The L-enantiomer of selenomethionine, known as Se-met and Sem, is a common natural food source of selenium. In vivo, selenomethionine is randomly incorporated instead of methionine and is readily oxidized. Its antioxidant activity arises from...

, borate(s)
Borate
Borates are chemical compounds which contain oxoanions of boron in oxidation state +3. The simplest borate ion, BO33−, has a trigonal planar structure. Other borates are made up of trigonal BO3 or tetrahedral BO4 structural units, sharing oxygen atoms...

, zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

, calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

, magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

, chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...

, manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

, molybdenum
Molybdenum
Molybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...

, betacarotene, and iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

. Other formulas may include additional ingredients such as other carotenes (e.g. lutein
Lutein
Lutein is a xanthophyll and one of 600 known naturally occurring carotenoids. Lutein is synthesized only by plants and like other xanthophylls is found in high quantities in green leafy vegetables such as spinach and kale...

, lycopene
Lycopene
Lycopene is a bright red carotene and carotenoid pigment and phytochemical found in tomatoes and other red fruits and vegetables, such as red carrots, watermelons and papayas...

), higher than RDA amounts of B, C or E vitamins including gamma-tocopherol, "near" B vitamins (inositol, choline, PABA), trimethylglycine (anhydrous betaine), betaine hydrochloride, vitamin K2 as menaquinone-7, lecithin
Lecithin
Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, and in egg yolk, composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids .The word lecithin was originally coined in 1847 by...

, citrus bioflavinoids or nutrient forms variously described as more easily absorbed.

Uses

By supplementing the diet with additional vitamins and minerals, multivitamins can be a valuable tool for those with dietary imbalances or different nutritional needs. People with dietary imbalances may include those on restrictive diets and those who cannot or will not eat a nutritious diet. Pregnant women and elderly adults have different nutritional needs than other adults, and a multivitamin may be indicated by a physician.

In the 1999–2000 National Health and Nutrition Examination Survey
National Health and Nutrition Examination Survey
The National Health and Nutrition Examination Survey is a survey research program conducted by the National Center for Health Statistics to asses the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews and...

, 52% of adults in the United States reported taking at least one dietary supplement in the last month and 35% reported regular use of multivitamin-multimineral supplements. Women versus men, older adults versus younger adults, non-Hispanic whites versus non-Hispanic blacks, and those with higher education levels versus lower education levels (among other categories) were more likely to take multivitamins. Individuals who use dietary supplements (including multivitamins) generally report higher dietary nutrient intakes and healthier diets. Additionally, adults with a history of prostate and breast cancers were more likely to use dietary and multivitamin supplements.

Precautions

While multivitamins can be a valuable tool to correct dietary imbalances, some risk exists. Various medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

s may adversely interact with multivitamins, and many people with medical conditions have special dietary needs. In particular, pregnant women should generally consult their doctors before taking any multivitamins: for example, either an excess or deficiency of vitamin A
Vitamin A
Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...

 can cause birth defects. Long-term use of beta-carotene, vitamin A, and vitamin E supplements may shorten life, with the additional risk being particularly large in smokers. Many common brand supplements in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 contain levels above the DRI
Dietary Reference Intake
The Dietary Reference Intake is a system of nutrition recommendations from the Institute of Medicine of the U.S. National Academy of Sciences. The DRI system is used by both the United States and Canada and is intended for the general public and health professionals...

/RDA amounts for some vitamins or minerals.

Severe vitamin and mineral deficiencies require medical treatment and can be very difficult to treat with common over-the-counter multivitamins. In such situations, special vitamin or mineral forms with much higher potencies are available, either as individual components or as specialized formulations, sometimes requiring a prescription.

Vitamins follow a biphasic dose-response curve
Dose-response relationship
The dose-response relationship, or exposure-response relationship, describes the change in effect on an organism caused by differing levels of exposure to a stressor after a certain exposure time...

. The curve is a bell curve, with the area in the middle being the safe-intake range and the edges representing deficiency and toxicity. For example, the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

 recommends that adults on a 2,000 calorie diet get between 60 and 90 milligrams of vitamin C per day. This is the middle of the bell curve. The upper limit is 2,000 milligrams per day for adults, which is considered potentially dangerous.

Multivitamins in large quantities may pose a risk of an acute overdose due to the toxicity of some components, principally iron
Iron poisoning
Iron poisoning is an iron overload caused by a large excess of iron intake and usually refers to an acute overload rather than a gradual one. The terms has been primarily associated with young children who consumed large quantities of iron supplement pills, which resemble sweets and are widely...

. However, in contrast to iron tablets, which can be lethal to children, toxicity from overdoses of multivitamins are very rare. There appears to be little risk to supplement users of experiencing acute side effects due to excessive intakes of micronutrients. There also are strict limits on the retinol content for vitamin A during pregnancies that are specifically addressed by prenatal formulas.

Evidence of benefits

In 2002, a paper by Robert H. Fletcher and Kathleen M. Fairfield from the Harvard School of Medicine, in the Journal of the American Medical Association stated that "it appears prudent for all adults to take vitamin supplements." In this article, which examined the clinical applications of vitamins for the prevention of chronic diseases in adults examined English-language articles about vitamins in relation to chronic diseases published between 1966 and 2002, and concluded that inadequate intake of several vitamins has been linked to the development of diseases including coronary heart disease, cancer, and osteoporosis.

Similarly, the April 9, 1998 issue of the New England Journal of Medicine featured an editorial entitled "Eat Right and Take a Multivitamin" that was based on studies that showed health benefits resulting from the consumption of supplemental folate to prevent birth defects and possibly decrease the incidence of cardiovascular disease.

A 2007 UC Berkeley School of Public Health study in collaboration with Shaklee Corporation determined that long-term vitamin and mineral supplement users showed markedly better health than people who took no supplements. "After adjustment for age, gender, income, education and body mass index, greater degree of supplement use was associated with more favorable concentrations of serum homocysteine, C-reactive protein, high-density lipoprotein cholesterol, and triglycerides, as well as lower risk of prevalent elevated blood pressure and diabetes."

There is a new gravitation in the United States towards the Mediterranean diet
Mediterranean diet
The Mediterranean diet is a modern nutritional recommendation inspired by the traditional dietary patterns of southern Italy, Crete and much of the rest of Greece in the 1960s....

. This diet is based on the Mediterranean Diet Pyramid
Mediterranean Diet Pyramid
The Mediterranean Diet Pyramid is a nutrition guide that was developed by Oldways, the Harvard School of Public Health, and the World Health Organization in 1993...

, created by Walter Willett
Walter Willett
Walter Willett, MD, DrPH., is an American physician and nutrition researcher. Currently, Willett is the Fredrick John Stare Professor of Epidemiology and Nutrition, and Chair of the Department of Nutrition at Harvard School of Public Health...

 in 1995. In 2008, the Harvard School of Public Health
Harvard School of Public Health
The Harvard School of Public Health is one of the professional graduate schools of Harvard University, located in the Longwood Area of the Boston, Massachusetts neighborhood of Mission Hill, which is next to Harvard Medical School. HSPH is considered a significant school focusing on health in the...

 updated Willett’s pyramid in a Nutrition Source article called “Food Pyramids: What Should You Really Eat?”. Included in this new pyramid, and the original pyramid, is a daily multivitamin. The Harvard article states that “A daily multivitamin, multi-mineral supplement offers a kind of nutritional backup, especially when it includes some extra vitamin D. While a multivitamin can't in any way replace healthy eating, or make up for unhealthy eating, it can fill in the nutrient holes that may sometimes affect even the most careful eaters.”

A 2009 study published in The American Journal of Clinical Nutrition reports that multivitamin use is associated with longer telomere
Telomere
A telomere is a region of repetitive DNA sequences at the end of a chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes. Its name is derived from the Greek nouns telos "end" and merοs "part"...

 length in women. Longer telomeres have recently been associated with longer life, and therefore multivitamins could have an anti-aging effect. However, this is the first study on this topic, so more studies must be done to confirm this effect.

In response to a 2009 study stating the uselessness of multivitamins, the Linus Pauling Institute
Linus Pauling Institute
The Linus Pauling Institute is a research institute located at Oregon State University with a focus on health maintenance. The mission statement of the institute is three-fold. First, to determine the functional roles of micronutrients and phytochemicals in promoting optimal health and to treat or...

 published an article refuting the study’s legitimacy and claims. According to the Linus Pauling Institute, the 2009 study was an observational study, not a randomized controlled trial. “Every epidemiologist will tell you that observational studies cannot establish cause-and-effect relationships; they only can observe associations.” Additionally, 41.5 percent of the female participants took multivitamins and were overall healthier in all their habits . This makes it difficult to separate their healthy habits from their multivitamin use. Perhaps they used multivitamins because they already had healthy habits and were therefore healthier overall. The Linus Pauling article concludes with this statement: “Even Dr. JoAnn Manson, a principal investigator of the Women's Health Initiative and co-author of the study, acknowledges that ‘the research doesn't mean multivitamins are useless. Multivitamins may still be useful as a form of [health] insurance for people with poor eating habits.’ And let's not fool ourselves, that's the large majority of the people in this country!”.

Bruce Ames
Bruce Ames
Bruce Nathan Ames is an American biochemist. He is a professor of Biochemistry and Molecular Biology at the University of California, Berkeley, and a senior scientist at Children's Hospital Oakland Research Institute...

, professor of Biochemistry
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

 and Molecular Biology
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

 at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...

, and a senior scientist at Children's Hospital Oakland Research Institute (CHORI), suggests that "to maximize human health and lifespan, scientists must abandon outdated models of micronutrients" and that "a metabolic tune-up through an improved supply of micronutrients is likely to have great health benefits."

Evidence of little or no benefit (neutral)

In 2006 the National Institutes of Health
National Institutes of Health
The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...

 convened an expert panel to examine the available evidence on nutrient supplements. This review concluded that "Most of the studies we examined do not provide strong evidence for beneficial health-related effects of supplements taken singly, in pairs, or in combinations of three or more." They noted that multivitamins could provide health benefits to some groups of people, such as postmenopausal
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...

 women, but that there was "disturbing evidence of risk" in other groups, such as smokers. The panel's report concluded that the "present evidence is insufficient to recommend either for or against the use of Multivitamin/Mineral Supplements by the American public to prevent chronic disease."

Similarly, a 2006 report for the United States Department of Health and Human Services
United States Department of Health and Human Services
The United States Department of Health and Human Services is a Cabinet department of the United States government with the goal of protecting the health of all Americans and providing essential human services. Its motto is "Improving the health, safety, and well-being of America"...

 concluded that "regular supplementation with a single nutrient or a mixture of nutrients for years has no significant benefits in the primary prevention of cancer, cardiovascular disease, cataract, age-related macular degeneration or cognitive decline." However, the report noted that multivitamins have beneficial effects in people with poor nutritional status, vitamin D and calcium can help prevent fractures in older people, and that zinc and antioxidants can help prevent age-related macular degeneration
Macular degeneration
Age-related macular degeneration is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults...

 in people at a high risk of developing this disease.

In 2007 the United Kingdom Food Standards Agency
Food Standards Agency
The Food Standards Agency is a non-ministerial government department of the Government of the United Kingdom. It is responsible for protecting public health in relation to food throughout the United Kingdom and is led by a board appointed to act in the public interest...

 published an updated set of recommendations for eating a healthy diet. The recommendations stated that pregnant women should take extra folic acid and iron and that older people might need extra vitamin D and iron. However, the report advised that "Vitamin and mineral supplements are not a replacement for good eating habits" and stated that supplements are unnecessary for healthy adults who eat a balanced diet.

One study from 2008 found that multivitamin use had no effect on prevention of lung cancer
Lung cancer
Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary...

. Participants in this observational study had been taking multivitamin supplements for an average of 10 years, and this use appeared to have no effect on the prevention of lung cancer.

In February 2009, a study conducted in 161,808 postmenopausal women from the Women's Health Initiative clinical trials concluded that after 8 years of follow-up "multivitamin use has little or no influence on the risk of common cancers, cardiovascular disease, or total mortality".

Another 2010 study in the Journal of Clinical Oncology
Journal of Clinical Oncology
The Journal of Clinical Oncology is a medical journal published 3 times a month by the American Society of Clinical Oncology , with a 2009 impact factor of 17.793...

 suggested that multivitamin use during chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....

 for stage III colon cancer had no effect on the outcomes of treatment. The study observed over 1,000 men in treatment for colon cancer and recorded their multivitamin use. About half the men in the study used multivitamins, and it appeared to have no effect on the outcomes of their treatment.

Evidence of potential harm

A 2008 study found that multivitamin use increased the mean breast density in premenopausal women. Increased breast density is associated with a higher risk for breast cancer. The study surveyed premenopausal and postmenopausal women about their multivitamin use, and found that multivitamin use was associated with higher mean breast density in premenopausal women but not postmenopausal women. The length of time that the women had been taking multivitamins did not seem to affect their mean breast densities.

In 2010, a Swedish study published in The American Journal of Clinical Nutrition found that multivitamin use may be associated with increased risk of breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...

 among women. The study followed 35,329 women between 1997 and 2009. At the end of the study, 974 women had been diagnosed with breast cancer, suggesting an increased risk of breast cancer relating to multivitamin use.

However, two larger subsequent studies both published in 2011 reported that there is no increased risk of breast cancer associated with multivitamin/mineral usage (although there was no proven benefit or reduced risk either):

"To assess the relation of multivitamin use with mortality and cancer, the authors prospectively examined these associations among 182,099 participants enrolled in the Multiethnic Cohort Study between 1993 and 1996 in Hawaii and California. During an average 11 years of follow-up, 28,851 deaths were identified. In Cox proportional hazards models controlling for tobacco use and other potential confounders, no associations were found between multivitamin use and mortality from all causes (for users vs. nonusers: hazard ratio = 1.07, 95% confidence interval: 0.96, 1.19 for men; hazard ratio = 0.96, 95% confidence interval: 0.85, 1.09 for women), cardiovascular diseases, or cancer. The findings did not vary across subgroups by ethnicity, age, body mass index, preexisting illness, single vitamin/mineral supplement use, hormone replacement therapy use, and smoking status. There also was no evidence indicating that multivitamin use was associated with risk of cancer, overall or at major sites, such as lung, colorectum, prostate, and breast. In conclusion, there was no clear decrease or increase in mortality from all causes, cardiovascular disease, or cancer and in morbidity from overall or major cancers among multivitamin supplement users."

The second was "a meta-analysis of cohort and case-control studies to evaluate multivitamin intake and its relationship with breast cancer risk."
"RESULTS: Eight of 27 studies that included 355,080 subjects were available for analysis. The total duration of multivitamin use in these trials ranged from 3 to 10 years. The frequency of current use in these studies ranged from 2 to 6 times/week. In analyses by duration of use 10 years or longer or 3 years or longer and by frequency 7 or more times/week that were reported in these studies, multivitamin use was not significantly associated with the risk of breast cancer. Only 1 recent Swedish cohort study concluded that multivitamin use is associated with an increased risk of breast cancer. The results of a meta-analysis that pooled data from 5 cohort studies and 3 case-control studies indicated that the overall multivariable relative risk and odds ratio were 0.10 (95% CI 0.60 to 1.63; p = 0.98) and 1.00 (95% CI 0.51 to 1.00; p = 1.00), respectively. The association was not statistically significant.
CONCLUSIONS: Multivitamin use is likely not associated with a significant increased or decreased risk of breast cancer, but these results highlight the need for more case-control studies or randomized controlled clinical trials to further examine this relationship."

Multivitamins and Children

It is not yet clear whether or not multivitamins should be used by children, and if so, what dosages are appropriate. Several studies have been done to determine the efficacy of multivitamins against different conditions.

One study done in 2002 followed 5-to-7-year old girls to determine the influence of their mothers on their multivitamin intake. About 200 mother and daughter pairs participated in this observational study. It was found that mothers who used multivitamin supplements were more likely to give them to their daughters. Daughters’ multivitamin supplement use was predicted by mothers’ beliefs, attitudes, perceptions, and practices regarding mothers’ own eating and child feeding practices, rather than by daughters’ diet quality. In the discussion, the study's authors recommended that mothers foster healthier patterns of food intake in daughters, rather than providing multivitamin supplements, because the daughters' vitamin and mineral intakes during the study exceeded recommendations.

Another study done in 2009 found that multivitamin use among eight year-old children does not decrease risk for development of allergies. However, it seemed that multivitamin use in the first few years of life decreased the risk of allergies in the children. This study observed over 2,000 children from birth to age 8, and evaluated their multivitamin use in relation to their development of allergic disease.

According to a study published in The American Journal of Clinical Nutrition in 2007, Tanzanian children born to parents who received multivitamin supplements during pregnancy had a reduced risk of anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...

, compared to the control group who received placebo supplements. However, a 2009 study published in the same journal found that iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 and folic acid
Folic acid
Folic acid and folate , as well as pteroyl-L-glutamic acid, pteroyl-L-glutamate, and pteroylmonoglutamic acid are forms of the water-soluble vitamin B9...

 supplements were just as good at preventing anemia in children as multivitamin supplements were. Therefore, it is unclear at this time if multivitamin supplements are helpful in treatment and prevention of anemia in children.

United States

Because of their categorization as a dietary supplement
Dietary supplement
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...

 by the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

 (FDA), most multivitamins sold in the U.S. are not required to undergo the testing procedures typical of pharmaceutical drugs.

However, some multivitamins contain very high doses of one or several vitamins or minerals, or are specifically intended to treat, cure, or prevent disease, and therefore require a prescription or medicinal license in the U.S. Since such drugs contain no new substances, they do not require the same testing as would be required by a New Drug Application
New drug application
The New Drug Application is the vehicle in the United States through which drug sponsors formally propose that the Food and Drug Administration approve a new pharmaceutical for sale and marketing...

, but were allowed on the market as drugs due to the Drug Efficacy Study Implementation
Drug Efficacy Study Implementation
Drug Efficacy Study Implementation was a program begun by the Food and Drug Administration in the 1960s after the requirement that all drugs be efficacious as well as safe. The DESI program was intended to classify all pre-1962 drugs that were already on the market as either effective,...

 program.

See also

  • Bodybuilding supplement
    Bodybuilding supplement
    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...

  • Dietary supplement
    Dietary supplement
    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...

  • Essential nutrient
    Essential nutrient
    An essential nutrient is a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health , and thus must be obtained from a dietary source...

  • Food supplements
  • Food additive
    Food additive
    Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...

  • Food fortification
    Food fortification
    Food fortification or enrichment is the process of adding micronutrients to food. It can be purely a commercial choice to provide extra nutrients in a food, or sometimes it is a public health policy which aims to reduce numbers of people with dietary deficiencies in a population.Diets that lack...

  • Functional food
    Functional food
    Functional food is a food where a new ingredient has been added to a food and the new product has a new function ....

  • Food processing
    Food processing
    Food processing is the set of methods and techniques used to transform raw ingredients into food or to transform food into other forms for consumption by humans or animals either in the home or by the food processing industry...

  • Health food
    Health food
    The term health food is generally used to describe foods that are considered to be beneficial to health, beyond a normal healthy diet required for human nutrition. However, the term is not precisely defined by national regulatory agencies such as the U.S...

  • Megavitamin therapy
    Megavitamin therapy
    Megavitamin therapy is the use of large doses of vitamins, often many times greater than the recommended dietary allowance in the attempt to prevent or treat diseases...

  • Orthomolecular medicine
    Orthomolecular medicine
    Orthomolecular medicine is a form of complementary and alternative medicine that seeks to maintain health and prevent or treat diseases by optimizing nutritional intake and/or prescribing supplements...

  • Naturopathic medicine
    Naturopathic medicine
    Naturopathy, or Naturopathic Medicine, is a form of alternative medicine based on a belief in vitalism, which posits that a special energy called vital energy or vital force guides bodily processes such as metabolism, reproduction, growth, and adaptation...

  • Nutraceutical
    Nutraceutical
    Nutraceutical, a portmanteau of the words “nutrition” and “pharmaceutical”, is a food or food product that reportedly provides health and medical benefits, including the prevention and treatment of disease. Health Canada defines the term as "a product isolated or purified from foods that is...

  • Nutrification (a.k.a. food enrichment).

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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