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Vitamins and Minerals

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Vitamins and Minerals

Vitamins and minerals are essential substances that our bodies need to develop and function normally. The known vitamins include A, C, D, E, and K, and the B vitamins: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxal (B6), cobalamin (B12), biotin, and folate/folic acid. A number of minerals are essential for health: calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, iodine, sulfur, cobalt, copper, fluoride, manganese, and selenium. The Dietary Guidelines for Americans 2015–2020 recommends that people should aim to meet their nutrient requirements through a healthy eating pattern that includes nutrient-dense forms of foods.

Multivitamin/Multimineral Supplements

Multivitamins/multiminerals (MVMs) are the most frequently used dietary supplements, with close to half of American adults taking them. MVMs cannot take the place of eating a variety of foods that are important to a healthy diet. Foods provide more than vitamins and minerals. Many foods also have fiber and other substances that can provide health benefits. However, some people who don’t get enough vitamins and minerals from food alone, or who have certain medical conditions, might benefit from taking one or more of these nutrients found in single-nutrient supplements or in MVMs. However, evidence to support their use for overall health or disease prevention in the general population remains limited.

Bottom Line:

  • Most individuals can get all of the necessary vitamins and minerals through a healthy eating pattern of nutrient-dense foods. The Dietary Guidelines for Americans 2015–2020 provides recommendations for specific populations, including women who are or may become pregnant, women who breastfeed, and people ages 50 and over.
  • Taking an MVM increases overall nutrient intake and helps some people get the recommended amounts of vitamins and minerals when they can’t or don’t get them from food alone. But taking an MVM can also raise the chances of getting too much of some nutrients, like iron, vitamin A, zinc, niacin, and folate/folic acid, especially when a person takes more than a basic, once-daily product that provides 100 percent of the daily value (DV) of nutrients.
  • The Age-Related Eye Disease Study (AREDS), which was led by NIH’s National Eye Institute and concluded in 2001, showed that daily high doses of vitamins C and E, beta-carotene, and the minerals zinc and copper—called the AREDS formulation—can help slow the progression to advanced age-related macular degeneration (AMD), a blinding eye disease.
  • Data from the later AREDS2 study showed that a supplement formulation containing the carotenoids lutein and zeaxanthin instead of beta-carotene was safer and more effective in slowing the progression of AMD.
  • There’s no standard or regulatory definition for MVMs, or any dietary supplement, as to what nutrients they must contain or at what levels. Manufacturers choose which vitamins, minerals, and other ingredients, as well as their amounts, to include in their products. Simply stated, dietary supplements aren’t required to be standardized in the United States. However, they are required to bear a Supplement Facts label and ingredient list describing what’s in the product.
  • Read the Supplement Facts label to identify MVMs in your supplement product. Be sure to check the percent daily value (% DV) to see what proportion of your daily allotment you’re getting.
  • People with healthier diets and lifestyles are more likely to take dietary supplements, making it hard to identify any benefits from their use. There’s no convincing evidence that MVMs help prevent chronic disease.

Safety

  • Taking a daily dose of a basic MVM is unlikely to pose a health risk for most people. However, if you consume fortified foods and beverages (such as cereals or drinks with added vitamins and minerals) along with dietary supplements, you should make sure that your total intake of vitamins and minerals is not more than the safe upper limits for any nutrients. Read the Nutrition Facts label on packaged foods or the Supplement Facts label of MVMs to see if the level far exceeds 100% DV. For more information on safe upper levels of nutrients, visit the NIH Office of Dietary Supplements at: ods.od.nih.gov/factsheets/list-all.
  • Smokers, and possibly former smokers, should avoid MVM products that provide more than 100% DV for vitamin A (either as preformed retinol or beta-carotene or some combination of the two) because two studies have linked high supplemental doses of these nutrients with an increased risk of lung cancer in smokers.
  • Taking excess amounts of vitamin A (preformed retinol form, not as beta-carotene) during pregnancy has been shown to increase the risk of birth defects.
  • Except in cases of iron deficiency or inadequacy, or unless a physician recommends otherwise, adult males and postmenopausal women should avoid using iron supplements or MVMs containing more than their recommended daily allowance for iron (8 mg/day). Iron supplements may be recommended for women of childbearing age, pregnant women, preterm infants, older infants, and teenage girls because they are at greater risk of developing deficiency. Yet, iron supplements are a leading cause of poisoning in young children, so parents and guardians should keep iron-containing supplements out of the reach of children.
  • MVMs providing nutrients at or up to 100% DV do not typically interact with medications. However, if you take a blood thinner, such as warfarin (Coumadin and other brand names), talk to your health care provider before taking any MVM or dietary supplement that contains vitamin K (this vitamin lowers the medicine’s effectiveness, and doctors base the medicine’s dose partly on the overall amount of vitamin K a person usually consumes in foods and supplements).

For More Information

NCCIH Clearinghouse

The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

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Know the Science

NCCIH and the National Institutes of Health (NIH) provide tools to help you understand the basics and terminology of scientific research so you can make well-informed decisions about your health. Know the Science features a variety of materials, including interactive modules, quizzes, and videos, as well as links to informative content from Federal resources designed to help consumers make sense of health information.

Explaining How Research Works (NIH)

Know the Science: 9 Questions To Help You Make Sense of Health Research

Understanding Clinical Studies (NIH)

PubMed®

A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed.

Website: https://pubmed.ncbi.nlm.nih.gov/

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NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

Last Updated: February 2018