Americans have been taking multivitamin/mineral (MVM) supplements since the early 1940s, when the first such products became available . MVMs are still popular dietary supplements and, according to estimates, more than one-third of all Americans take these supplements [1,2].
MVMs account for almost one-sixth of all purchases of dietary supplements and 40% of all sales of vitamin and mineral supplements. (Sales of all dietary supplements in the United States totaled an estimated $36.7 billion in 2014. This amount included $14.3 billion for all vitamin- and mineral-containing supplements, of which $5.7 billion was for MVMs .)
No standard or regulatory definition is available for an MVM supplement—such as what nutrients it must contain and at what levels. Therefore, the term can refer to products of widely varied compositions and characteristics . These products go by various names, including multis, multiples, and MVMs. Manufacturers determine the types and levels of vitamins, minerals, and other ingredients in their MVMs. As a result, many types of MVMs are available in the marketplace.
One way to group them is as follows:
- Many are once-daily MVMs that contain all or most of the recognized vitamins and minerals, generally at levels close to the Daily Values (DVs) or Recommended Dietary Allowances (RDAs) or Adequate Intakes (AIs) for these nutrients.1 This fact sheet focuses primarily on these basic “broad-spectrum” MVMs. Formulations for children, adults, men, women, pregnant women, and seniors typically provide different amounts of the same vitamins and minerals based on the specific needs of these populations.
- Some MVMs contain levels of certain vitamins and minerals that are substantially higher than the DV, RDA, AI, and even, in some cases, the established tolerable upper intake level (UL).2 These MVMs might also include other nutritional and herbal ingredients. Manufacturers sometimes offer these MVMs in packages or packs of two or more pills that users are supposed to take each day.
- Specialized MVMs—such as those for enhanced performance or energy, weight control, improved immune function, or management of menopause symptoms—often include vitamins and minerals in combination with herbal and specialty ingredients, such as sterols, coenzyme Q10, probiotics, and glucosamine. A few nutrients might be present at levels substantially above the DV, RDA, AI and, in some cases, the UL.
To complicate further this product category, many dietary supplements are not labeled as MVMs even though they contain similar types and amounts of vitamins and minerals to some products labeled as MVMs . For example, a manufacturer might label a product containing vitamins C and E, selenium, and beta-carotene as an antioxidant formula rather than an MVM even though it contains several vitamins and a mineral.
Given the diversity of available MVMs, investigators define these products differently (or sometimes not at all) in studies to evaluate their potential health benefits.
For example, the Agency for Healthcare Research and Quality, in an evidence-based review in 2006 of the role of MVM supplements in chronic disease prevention, defined MVMs as “any supplement containing three or more vitamins and minerals but no herbs, hormones, or drugs, with each component at a dose less than the tolerable upper level determined by the Food and Nutrition Board…” .
Another study defined MVMs more ambiguously as “stress-tab-type,” “therapeutic or theragran type,” and “one-a-day” type . Varying definitions of MVMs, and the fact that manufacturers can change the composition of their MVMs at will, complicate the study of the potential impacts of MVMs on health because equivalent products are not used across studies.