It is a truth sheet meant for well being professionals. For a reader-friendly overview of Multivitamin/mineral Dietary supplements, see our client truth sheet on Multivitamin/mineral Dietary supplements.
COVID-19
Introduction
People have been taking multivitamin/mineral (MVM) dietary supplements for the reason that early Nineteen Forties, when the primary such merchandise grew to become accessible [1]. MVMs are nonetheless standard dietary dietary supplements and, in response to estimates, greater than one-third of all People take these dietary supplements [1,2]. MVMs account for nearly one-sixth of all purchases of dietary dietary supplements and 40% of all gross sales of vitamin and mineral dietary supplements. (Gross sales of all dietary dietary supplements in america totaled an estimated $36.7 billion in 2014. This quantity included $14.3 billion for all vitamin- and mineral-containing dietary supplements, of which $5.7 billion was for MVMs [3].)
No normal or regulatory definition is on the market for an MVM complement—resembling what vitamins it should include and at what ranges. Subsequently, the time period can consult with merchandise of extensively diverse compositions and traits [4]. These merchandise go by numerous names, together with multis, multiples, and MVMs. Producers decide the kinds and ranges of nutritional vitamins, minerals, and different components of their MVMs. In consequence, many varieties of MVMs can be found within the market.
One technique to group them is as follows:
To complicate additional this product class, many dietary dietary supplements aren’t labeled as MVMs though they include comparable varieties and quantities of nutritional vitamins and minerals to some merchandise labeled as MVMs [4]. For instance, a producer would possibly label a product containing nutritional vitamins C and E, selenium, and beta-carotene as an antioxidant formulation reasonably than an MVM though it accommodates a number of nutritional vitamins and a mineral.
Given the range of obtainable MVMs, investigators outline these merchandise in a different way (or typically by no means) in research to judge their potential well being advantages. For instance, the Company for Healthcare Analysis and High quality, in an evidence-based overview in 2006 of the function of MVM dietary supplements in persistent illness prevention, outlined 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…” [5]. One other research outlined MVMs extra ambiguously as “stress-tab-type,” “therapeutic or theragran type,” and “one-a-day” sort [6]. Various definitions of MVMs, and the truth that producers can change the composition of their MVMs at will, complicate the research of the potential impacts of MVMs on well being as a result of equal merchandise aren’t used throughout research.
Extent of MVM Use
In line with an evaluation of information that the Nationwide Well being and Vitamin Examination Survey (NHANES) collected in 2003–2006, 33% of the U.S. inhabitants aged 1 12 months and older took an MVM in a given month (see Determine 1) [2]. The authors of this evaluation outlined MVMs as merchandise containing a minimum of three nutritional vitamins and a minimum of one mineral. General, females (36%) had been extra prone to take an MVM than males (31%). Use charges of MVMs had been 25%–27% at age 1–3 years and 14%–19% at 14–18 years. After age 18, use charges elevated by age in order that by age 71 years or older, 48% of girls and 43% of males had been taking MVMs.
Estimating the prevalence of MVM use is difficult due to variations in definitions of those merchandise, various frequency of use, and the rising complexity of MVM formulations (e.g., an increasing number of merchandise include non-vitamin, non-mineral components and specialised formulations) [1]. General, nevertheless, research present that MVM use is extra frequent amongst girls and the youngsters of girls who use dietary supplements; the aged; these with extra training, larger incomes, more healthy existence and diets, and decrease body-mass indexes; and residents of the western United States. MVM use is decrease amongst people who smoke and members of sure ethnic and racial teams, resembling African People, Hispanics, and Native People [1].
MVMs and Well being – “multivitamin and mineral supplement”
Individuals take MVMs for quite a few causes. Right here we consider the impression of MVMs on two of those elements: to extend nutrient intakes and to enhance well being, forestall persistent illness, or each.
Enhance Nutrient Intakes
Taking an MVM will increase nutrient intakes and helps folks receive beneficial intakes of nutritional vitamins and minerals after they can not meet these wants from meals alone. The Meals and Vitamin Board (FNB) notes that RDAs and AIs for vitamins are ranges of consumption one ought to ingest, on common, every day from the eating regimen [7]; the FNB doesn’t deal with whether or not or to what extent nutrient dietary supplements can compensate for dietary inadequacies. However, some contemplate use of an MVM as a type of dietary or dietary “insurance,” an idea first launched by Miles Laboratories in advertising and marketing its One-A-Day® line of nutrient dietary supplements [8].
Though MVMs can enhance the consumption adequacy of assorted vitamins, they will additionally improve the probability that customers may have intakes of different vitamins at ranges which are larger than ULs. Outcomes from a number of research exemplify each the problems of dietary insurance coverage for some people and the priority of extreme intakes for others.
In a single research, for instance, investigators assessed the diets and use of multivitamins in a big multiethnic cohort from Los Angeles and Hawaii [9]. The investigators calculated nutrient intakes from eating regimen utilizing a meals frequency questionnaire and from multivitamins utilizing a default profile based mostly on the 2 mostly reported MVMs. Roughly three-quarters of contributors had sufficient intakes from meals alone, however use of multivitamins elevated the prevalence of adequacy by a mean of eight share factors for each women and men. The best enhancements in consumption had been for vitamin E, vitamin A, and zinc. Nonetheless, the prevalence of doubtless extreme intakes among the many MVM customers was 10%–15% for vitamin A, iron, and zinc and 48%–61% for niacin. The investigators concluded that MVMs “could be better formulated to target public health concerns.” They added that a perfect MVM would assist fill gaps in nutrient adequacy (e.g., for vitamin E, potassium, and calcium) and supply low ranges of vitamins whose quantities in MVMs could possibly be extreme (e.g., vitamin A, iron, and niacin).
A second research, a nationwide survey of infants and youngsters youthful than 4 years, discovered that normal nutrient intakes from meals alone had been sufficient for many of the infants and youngsters [10]. Nonetheless, the outcomes confirmed insufficient intakes of iron and zinc in a small subset of older infants and for vitamin E and potassium in a sizeable proportion of younger kids. Though dietary supplements would assist cut back the prevalence of those inadequacies, use of dietary supplements tended to push intakes of some vitamins— significantly vitamin A, folic acid, and (for the older preschool kids) zinc—over the UL. The investigators suggested dad and mom to not give younger kids dietary dietary supplements or fortified meals containing excessive ranges of vitamin A and zinc [11].
A research of folic acid, the artificial type of folate added to fortified meals and accessible in complement kind, offers one other instance of analysis on the impression of MVMs on dietary adequacy. In line with an evaluation of information from the 2003–2006 NHANES, 34.5% of contributors reported utilizing dietary supplements (MVMs and others) containing folic acid [12]. Though these dietary supplements lowered the prevalence of insufficient intakes of this nutrient, 4% of customers exceeded the UL (1,000 mcg/day) for folic acid from the dietary supplements alone. Roughly 5% of individuals aged 50 years or older had whole folic acid intakes above the UL. Amongst kids aged 1–13 years, 28% of whom took folic acid-containing dietary dietary supplements, greater than half exceeded the UL for folic acid in contrast with 5% of nonusers [13]. Not surprisingly, extreme nutrient intakes are extra doubtless amongst MVM customers who additionally take single vitamin and mineral dietary supplements [14].
A number of research have discovered that MVM customers are likely to have larger micronutrient intakes from their eating regimen than nonusers [14]. Satirically, the populations at highest threat of dietary inadequacy who would possibly profit essentially the most from MVMs are the least prone to take them [1].
Well being Promotion and Power Illness Prevention
In 2006, researchers printed a complete evidence-based overview of the connection between research on vitamins that the majority strongly recommended potential impacts on well being and on circumstances (most cancers; age-related sensory loss; and cardiovascular, endocrine, neurologic, musculoskeletal, gastroenterologic, renal, and pulmonary illnesses) on which consultants consider that nutrient dietary supplements have essentially the most potential affect [5]. Contemplating solely printed randomized, managed medical trials, the investigators discovered that use of MVMs didn’t cut back the chance of any persistent illness. (The authors outlined MVMs as merchandise containing three or extra nutritional vitamins and minerals at ranges beneath the UL and no herbs).
An skilled panel that reviewed this report and took part in a state-of-the-science convention on MVMs in persistent illness prevention on the Nationwide Institutes of Well being in 2006 concluded that “the present evidence is insufficient to recommend either for or against the use of MVMs by the American public to prevent chronic disease” [1]. An earlier evaluation of the proof by the U.S. Preventive Providers Job Power [15] got here to an analogous conclusion: the proof for or in opposition to using MVMs to forestall most cancers or heart problems was inadequate. A complete analysis of analysis by the World Most cancers Analysis Fund and the American Institute for Most cancers Analysis [16] beneficial in opposition to using dietary dietary supplements for most cancers prevention by the general public due to the unpredictability of potential advantages and dangers, in addition to the potential of surprising adversarial occasions.
Many of the research of the potential worth of MVMs to boost well being and forestall illness have been observational, which might solely recommend an affiliation however don’t show a cause-effect relationship. Some have recommended potential advantages or adversarial results, whereas others have discovered none. Contributors in these research used totally different MVMs or the research included totally different mixes and doses of vitamins. One of many largest of those potential observational research included 161,808 postmenopausal girls aged 50–79 years who had been collaborating within the Girls’s Well being Initiative to check well being and dangers for most cancers, coronary heart illness, and osteoporosis. Roughly 41.5% of the ladies took an MVM, however over the median of 8 years of commentary, the investigators discovered no affiliation between use of those merchandise and the chance of any widespread most cancers or whole cancers, heart problems, or whole mortality [17]. Related outcomes had been reported by investigators who adopted 182,099 women and men aged 45–75 years residing in Hawaii and California over a mean 11 years of followup. Amongst this cohort of largely African People, Native Hawaiians, Japanese People, Latinos, and non-Hispanic whites, roughly 48% of the lads and 52% of the ladies reported taking a multivitamin with or with out minerals [18].
A potential research of Swedish girls discovered an affiliation between MVM use and an elevated breast most cancers threat [19]. One other research of U.S. well being professionals discovered no such affiliation however did discover indications that MVM use would possibly cut back the chance of estrogen- and progesterone-receptor–unfavourable breast most cancers and breast most cancers total in girls who eat alcohol [20]. A big potential research discovered a better threat of superior and deadly prostate cancers amongst males who took an MVM greater than seven instances every week than in nonusers [6]. A potential research of male physicians discovered that MVM use had no affiliation with heart problems [21]. Nonetheless, amongst Swedish grownup girls, use of MVMs was related to a diminished threat of myocardial infarction, particularly when taken for a minimum of 5 years [22]. A research through which postmenopausal girls in Iowa had been adopted for 18 years discovered that these taking MVMs (or particular vitamins like iron) had a slight however important elevated whole mortality threat as in comparison with nonusers [23].
Randomized managed trials are a superior research design to research whether or not MVMs would possibly have an effect on illness threat, however few have been carried out. The Physicians Well being Examine II was the longest medical trial to research whether or not MVMs would possibly assist forestall persistent illness. The research randomly assigned 14,641 male physicians in america aged 50 and older to take a each day MVM (Centrum Silver®) or placebo and adopted contributors for a median of 11.2 years. Contributors taking the MVM didn’t have fewer main cardiovascular occasions, myocardial infarctions, strokes, or cardiovascular-related deaths [24]. Nonetheless, MVM supplementation modestly however considerably diminished their threat of growing most cancers by 8%, though it didn’t cut back the chance of prostate most cancers or total most cancers mortality [25].
Two different well-known trials of the impression of MVMs on illness threat and development used combos of antioxidant vitamins. Within the first of those research, the French Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) research, investigators randomly assigned 13,017 adults to obtain a placebo or a each day complement containing average quantities of vitamin C (120 mg), vitamin E (30 mg), beta-carotene (6 mg), selenium (100 mcg), and zinc (20 mg) [26]. After 7.5 years of use, the dietary supplements lowered whole most cancers incidence and all-cause mortality in males however not girls. The dietary supplements offered no safety in opposition to heart problems.
Within the Age-Associated Eye Illness Examine, investigators randomly assigned people with various levels of age-related macular degeneration to obtain a placebo or a each day complement containing excessive doses of vitamin C (500 mg), vitamin E (400 worldwide items [IU]), beta-carotene (15 mg), zinc (80 mg), and copper (2 mg) [27]. (These vitamins are current in most elementary MVMs however often in considerably smaller quantities.) Over a mean followup interval of 6.3 years, the dietary supplements considerably diminished the chance of growing advanced-age–associated macular degeneration and diminished lack of visible acuity.
A small randomized managed trial in Sri Lankan adults with diabetes discovered that utilizing a specifically ready MVM with zinc for 4 months led to a big discount in fasting blood sugar and glycosylated hemoglobin in comparison with people who obtained both a placebo or the MVM with out zinc [28]. The MVM contained average quantities of assorted nutritional vitamins and minerals, together with 22 mg zinc. Nonetheless, a big potential research, observational in nature, discovered no affiliation between MVM use amongst adults aged 50–71 years and threat of growing diabetes [29].
As a result of folks with more healthy diets and existence are extra doubtless to make use of dietary dietary supplements, attributing potential well being advantages which are distinct from the confirmed and predictable advantages of health-promoting behaviors to using dietary supplements is troublesome [8]. Moreover, whether or not research discover any advantages (or dangers) will depend on the combos and quantities of vitamins within the MVMs used in addition to the populations studied and length of follow-up, and these outcomes aren’t generalizable to the big number of MVMs accessible within the market.
Particular Concerns for Sure Inhabitants Teams
Though MVMs don’t seem to scale back total persistent illness threat, a number of vitamins in MVMs would possibly profit sure inhabitants teams. For instance:
No U.S. authorities well being company, non-public well being group, or well being skilled group promotes common use of an MVM or particular person vitamins with out contemplating first the standard of an individual’s eating regimen. Nonetheless, people with poor nutrient intakes from eating regimen alone, who eat low-calorie diets, or who keep away from sure meals (resembling strict vegetarians and vegans) would possibly profit from taking MVMs [35]. Healthcare suppliers typically prescribe MVMs for folks with medical circumstances and illnesses that impair digestion, absorption, or use of vitamins. Usually, some dietary supplements would possibly assist individuals who don’t eat a nutritious number of meals to acquire sufficient quantities of important vitamins. Nonetheless, dietary supplements can not take the place of the number of meals which are necessary to a nutritious diet.
Security Points
Taking a fundamental MVM that gives vitamins approximating beneficial intakes ought to pose no security dangers to wholesome folks. Nonetheless, people who take MVMs and different dietary supplements and who eat fortified meals and drinks would possibly eat some vitamins at ranges exceeding the UL, rising the potential of adversarial results [36]. This will also be a priority for folks taking MVMs that include some nutritional vitamins or minerals at doses approaching or exceeding the UL.
People who smoke and, presumably, former people who smoke ought to keep away from MVM merchandise offering giant quantities of beta-carotene or vitamin A as a result of two research have linked these vitamins to an elevated threat of lung most cancers in people who smoke [37]. In a single randomized, managed medical trial, male Finnish people who smoke who took supplemental beta-carotene (20 mg/day) had an 18% larger lung most cancers price than people who smoke who took a placebo over 5–8 years of followup [38]. In one other research, people who smoke, former people who smoke, and asbestos-exposed individuals who took a mixture of 30 mg/day of beta-carotene plus 25,000 IU/day of vitamin A (as retinol) had a 28% improve in lung most cancers threat after a mean 4-year followup in comparison with contributors taking a placebo [39].
Taking extra vitamin A (as preformed retinol however not beta-carotene) throughout being pregnant can improve the chance of delivery defects in infants. The vitamin A UL throughout being pregnant is 9,240 IU/day for adolescents and 10,000 IU/day for grownup girls [40].
Until a doctor diagnoses iron deficiency or inadequacy, grownup males ought to keep away from taking MVMs containing the DV for iron. At 18 mg, this quantity is greater than twice their RDA of 8 mg/day. Postmenopausal girls, for whom the RDA for iron can also be 8 mg/day, must also keep away from MVMs containing the DV for iron until a doctor recommends in any other case. Iron dietary supplements are a number one reason behind poisoning in kids till age 6 years, so dad and mom and guardians ought to preserve iron-containing dietary supplements out of youngsters’s attain [41].
Interactions with Medicines
MVMs offering vitamins at beneficial consumption ranges don’t ordinarily work together with drugs, with one necessary exception. Individuals who take medicines to scale back blood clotting, resembling warfarin (Coumadin®), ought to speak with their healthcare suppliers earlier than taking any MVM or dietary complement containing vitamin Ok [42,43]. Vitamin Ok is concerned in blood clotting and reduces the effectiveness of warfarin and comparable medication. The dose of treatment is decided partly by the quantity of vitamin Ok routinely consumed.