The Best Multivitamin
Best for Women
Best for Men
Best for Kids
Best for Seniors
Food-based nutrients with minimal fillers, from a manufacturer that sets the industry standard for superior transparency.
The same food-based nutrients and transparency as with the women's vitamins, but a little pricier than the average men's multivitamin.
Not in the market for pricey, food-based multis? We liked these USP-certified, synthetic nutrients for adults at just $0.02 per serving.
Our kids' pick boasts food-based nutrients sans fillers or artificial dyes, with some added sweeteners for a fruity flavor.
Our nutritional needs change as we get older, and Kirkland offers synthetic nutrients priced affordably at just $0.03 per serving.
The Best Multivitamin
- MegaFood Women’s One Daily -
Best for Women
- MegaFood Multi for Men -
Best for Men
- Kirkland Signature Daily Multi -
- Rainbow Light Kids One MultiStars Food-Based Multivitamin -
Best for Kids
- Kirkland Signature™ Adults 50+ Mature Multi -
Best for Seniors
The best multivitamins have independent certifications for label accuracy and purity, plus a well-rounded formula that hits the majority of FDA-recommended ingredients. Food-derived or synthetic? The choice is yours — science says they're both effective, but you’ll pay several times more for food-based vitamins.
We’ll be upfront, though: Multivitamins aren’t miracle supplements. “You really cannot supplement your way out of an unhealthy diet,” says Robin Foroutan, a registered dietitian nutritionist and spokeswoman for the Academy of Nutrition and Dietetics. But Foroutan says she sometimes advises her clients to take one, especially if their diets lack important nutrients.
If your meals are more Guy Fieri than Jamie Oliver, try MegaFood Women's One Daily or MegaFood Multi for Men. MegaFood gets high marks from third-party certifiers, offers remarkable transparency in an industry not known for it (you can literally watch a live stream of its New Hampshire facilities), and limits its inactive filler ingredients to three — by far the lowest we’ve seen. Most notably, both formulas are derived entirely from real food sources, which is a big plus for some. The one downside? They’re expensive, costing $0.68 to $0.90 per serving, which is roughly six times as expensive as the average multivitamin.
Our budget pick, Costco’s synthetic Kirkland Signature Daily Multi, also received high marks from third parties and is much cheaper — only 2 cents per serving. The biggest difference: Its nutrients are derived entirely from synthetic sources. Science hasn’t proven synthetics to be better or worse than their natural counterparts, so if you don’t feel strongly one way or the other, we think Kirkland Signature is a great way to go. (It also includes calcium and potassium, which MegaFood lacks.)
For kids, our favorite was Rainbow Light Kids One Multivitamin. Each crunchy, star-shaped tablet contains the same essential nutrients we looked for in our adult picks, at child-friendly doses. This supplement is food-based, and free of the fillers and artificial dyes we saw in many other kids’ formulas. The brand came highly recommended by our experts and is intended for children of all ages. At $0.21 per serving, Rainbow Light is also less expensive than the average kids’ multivitamin.
Older adults have slightly different dietary requirements, often needing higher levels of vitamins like B12 and D. For this category, we suggest Kirkland Signature Adults 50+ Mature Multi — a synthetic formula that hit our nutritional benchmarks for older adults and is quite affordable at just $0.03 per dose.
All that said, the amounts of nutrients included in all our top picks vary — as will the amounts you need to be your healthiest. It’s important to consult with your doctor to determine if you have any vitamin deficiencies (usually via blood test) and what amounts you might require to get back up to speed. If it’s a severe deficiency, your doctor will likely recommend or prescribe a supplement for whichever specific nutrients you lack. Only mild deficiencies can be ameliorated by a multivitamin.
How We Found the Best Multivitamin
We started out with enough options to fill an entire aisle at your friendly neighborhood supplement store: 289 varieties of tablets, capsules, gummies, chewables, and liquids. Our goal was to find which ones were the safest and most effective to take.
We ditched anything with a “proprietary blend” to ensure we knew what we were recommending.
If you’re consuming a tablet or capsule every day, you’d better know exactly what’s in it, and how much. Unlike pharmaceuticals, supplements aren’t submitted for FDA testing and approval before they go to market. The FDA does require that manufacturers disclose all supplement ingredients and detail the amounts per serving — unless it’s classified as a “proprietary blend.” In that case, the manufacturer doesn’t have to disclose anything besides a list of ingredients and the total amount in the bottle.
This kind of disclosure loophole originated to protect businesses with unique products from being copied by competitors, but it’s also a convenient way for manufacturers to skimp on amounts or use inferior ingredients. Worse, buyers could end up consuming a product with too much of one ingredient — even an herbal add-in — which can pose health hazards. (For example, seemingly harmless herbs such as licorice and ginseng have been tied to high blood pressure.)
To make sure these vitamins contained the ingredients they claimed, we cut products that didn’t have credible third-party verification.
Without FDA oversight, the supplement industry is a bit like the Wild West of the wellness world. Journalist Catherine Price researched the supplement industry while writing her book Vitamania: How Vitamins Revolutionized the Way We Think About Food, and she told us if there’s one thing consumers should know, it’s this:
Dietary supplements are not tested for safety or for effectiveness before being sold. The motto of the industry should be caveat emptor: buyer beware.
So we sought out a few sheriffs to establish some accountability. There are a handful of labs that test supplements to evaluate whether they actually contain what the label promises, and we cut all multivitamins that weren’t approved by or compliant with at least one of the following:
- NSF International
- United States Pharmacopeia (USP)
- Labdoor (We looked for at least a 60 out 100 score, which represents a minimum balance of label accuracy, product purity, and nutritional value. Find out more about Labdoor’s grading system.)
NSF and USP (both nonprofit organizations) test supplements at the request of manufacturers, then lend stamps of approval to verified products’ packaging. Labdoor and ConsumerLab, both for-profit companies, seek out products to test without consent from manufacturers. (Manufacturers can request tests from ConsumerLab as well.)
We also looked for products that were in compliance with the International Organization for Standardization’s (ISO) system of in-house testing. This international non-governmental organization lays out a rigorous system of testing for quality management for any product; MegaFood, the manufacturer of our top picks, is in compliance with that system. It’s not an independent certification, but it usually demonstrates that a company cares about quality assurance and wants the public to know.
We limited the number of inactive ingredients to minimize the filler in your vitamins.
“Inactive ingredients” is a blanket term for everything included in the pill that isn’t adding nutritional value. Typically, a short list of inactive ingredients is a good sign of quality — our top picks from MegaFood have just three.
We looked for formulas that limited their use of artificial sweeteners, including sucralose, dextrose, maltodextrin, xylitol, glucose syrup, aspartame, and high fructose corn syrup. These ingredients don’t make your vitamin more nutritious; most of them just make it sweeter.
In that same spirit, we wanted to avoid partially hydrogenated oils and artificial colorants as much as possible. We also kept an eye out for fillers and binders that are probably safe in small doses — but why consume them if there are better options? Those included titanium dioxide, carmine, butylated hydroxytoluene, benzoic acid, PEG 3350, talc, and magnesium silicate.
None of our remaining multivitamins were cut at this stage.
And examined labels for a good blend of nutrients.
When it comes to nutrition, “the most important thing is eating a balanced diet with nutrient-rich foods, and then supplementing to fill missing gaps,” said Sharon Palmer, a registered dietitian nutritionist and author of Plant-Powered for Life. “If your diet is pretty good, it might not really be necessary — maybe supplement a few times a week if you’re really concerned about shortfalls.”
To figure out what those shortfalls could be, we turned to the FDA’s dietary guidelines. Out of the 27 nutrients the body needs, the FDA states that American adults are most likely to be at risk of not consuming enough calcium, potassium, or magnesium — as well as vitamins A, C, and E.
It was a solid wish list, but very few multivitamins contain significant amounts of everything. “Multis don’t typically contain 100 percent of what you need, as the pill would just be too large,” Palmer told us — and in fact, we even had trouble finding a good option that included all those key “at-risk” nutrients, particularly potassium and calcium.
It’s understandable: there’s no way one supplement could magically cover all the bases for all people. So to make our top picks, we analyzed our remaining list of 33 multivitamins, looking for the ones that featured the fewest inactive ingredients, the best third-party certifications, and the most well-rounded roster of nutrients.
The 5 Multivitamins We Tested
- MegaFood Women's One Daily
- MegaFood Multi for Men
- Kirkland Signature Daily Multi
- Rainbow Light Kids One Multivitamin
- Kirkland Signature Adults 50+ Mature Multi
Our Picks for the Best Multivitamin
One big reason these multivitamins went to the top of our list: In an industry filled with misdirection and misinformation, MegaFood is a beacon of transparency. Its supplements are certified as GMP (Good Manufacturing Practices) with NSF International, which assures “the product produced has the identity, strength, composition, quality, and purity that it is represented to possess,” and MegaFood adheres to ISO 9001 standards, meaning its labs comply with the highest standards of quality assurance and testing.
Those certifications alone are more than enough to stand out from the crowd, but it doesn’t stop there. MegaFood provides links to the farmers who supply the food it derives nutrients from. It’s certified vegan, gluten-free, and non-GMO. It’s herb- and pesticide-free. And its New Hampshire facilities even have an extensive network of cameras so you can personally watch its lab employees in action. The company is so keen to show what it’s all about, it coined its own slogan: Big T Transparency.
That transparency won big points with us, not just for being different than other multivitamins, but because it means we know exactly what’s in these vitamins — the ingredients and where they came from.
Food-Based Benefits?Advocates say they’re better because they contain fewer chemicals and are derived from real foods. But critics argue synthetic nutrients have a more reliable shelf life. What does the science say? “No one knows for sure,” said Foroutan. “The research is not there.”
Beyond Big T, MegaFood has another huge distinction: its multivitamins’ nutrients are derived exclusively from fruits, vegetables, and grains, meaning the vitamin A within is extracted from carrots; the vitamin C comes from organic oranges; and the vitamin K was once inside a cabbage. Many other nutrients, including the iron in the women’s multivitamin and the vitamin B12 in both blends, were derived from a yeast known as “saccharomyces cerevisiae,” a natural ingredient commonly used in brewing and baking. While the jury is still out on the tangible benefits of food-based supplements, they are must-haves for plenty of consumers, and MegaFood delivers.
Another thing we love about these multivitamins is the super-short list of inactive fillers. There are just three ingredients used to bind the tablet together, and all are found in nature: plant cellulose, vegetable lubricant, and the chemical compound silica (basically, sand). An inactive ingredient list this short is a rarity in the supplement world, and that helped push these multivitamins to the top of our pile. (To compare, Kirkland Signature has 13.)
Across both formulas, MegaFood boasts a nice balance of ingredients. Of the 27 nutrients the body needs, Multi for Men is purposefully missing iron, calcium, and magnesium — and while it does contain potassium, it has only a negligible amount. Women’s One Daily contains all 27, although it also contains barely any potassium.
What are the other big differences between the men’s and women’s blends?
There are slight variations in some nutrient levels, and the women’s blend contains a suite of 16 herbal additives, including nettle leaf and dandelion root. More notably, the women’s multivitamin contains 9 milligrams of iron, since premenopausal women need more iron than men or postmenopausal women. Finally, the women’s multivitamin requires just one tablet per day, but the mens requires two.
There is one clear downside to MegaFood multivitamins: They’ll cost you. The blend targeted at women costs around 68 cents per serving (one tablet) and the men’s blend costs a steep 90 cents per serving (two tablets). The women’s formula is about average for the industry, but the men’s is decidedly more expensive per serving than most multivitamins. Why the extra cost? Essentially, you’re paying for transparency and food-based ingredients. If those two factors are important to you, you won’t find a better multivitamin. If you’re looking for a more affordable option, keep reading.
If you’re just looking for a non-gendered, adult multivitamin, you can’t get a much better bargain than the synthetic Kirkland Signature Daily Multi from Costco. It contains all 27 wishlist nutrients, though it only has 80 milligrams of potassium — about 2 percent of the recommended daily value. Unlike MegaFood, the nutrients in these multivitamins are synthetic, meaning they’re created in a lab instead of extracted from a carrot or a head of broccoli. (This may make some people squeamish, but there’s no evidence that synthetics are better or worse than naturally sourced vitamins.)
The Kirkland Signature Daily Multi is USP-certified and received a 66 out of 100 grade from Labdoor, earning high marks for value and purity, but a few red flags for label claim variance. The worst offense was folic acid levels at 31 percent above the label claim. Again, this isn’t a dangerous level — but it shows some inconsistencies in formulation. And one last caveat: This vitamin contains 18 milligrams of iron. That’s 100% of the RDA for premenopausal women, but exceeds the 8 milligram RDA for postmenopausal women and men. Too much iron can cause constipation, but the National Institute of Health guidelines point out an 18 milligram dosage is common in multivitamins and only warn against acute intakes of more than 20 milligrams.
Bottom line? Kirkland Signature Daily has great nutrients at an unbeatable price. The tradeoff is that you may be getting a little more or a little less of any one nutrient — but still within safe levels.
Most experts recommend that children, like adults, get their nutrients from food whenever possible. But if your kids balk at carrots and broccoli, sometimes multivitamins are the simplest way to cover diet deficiencies. Because kids need lower doses of most nutrients than adults, however, it’s important to choose a formula specifically for children.
After sorting through the options, we recommend Rainbow Light Kid's One MultiStars. Foroutan recommended Rainbow Light as a “really good quality” brand, and after looking through the ingredient list, we agree. Like our top adult picks, this is a food-based multivitamin. It contains kid-friendly doses of a wide range of necessary nutrients — even potassium, important for children and adults, but absent in many formulas — and it’s free of fillers and artificial dyes. It does include sweeteners (in the form of sucrose and dextrose), but this comes with the territory: We couldn’t find a single children’s multivitamin that didn’t contain sweeteners of some sort. And if you want your child to willingly eat their multivitamin, that’s probably just as well. The tablets themselves are crunchy and star-shaped, with a surprisingly tasty “fruit punch” flavor that comes from natural orange, cherry, and pineapple flavor. The supplement is intended for children of all ages, and a bottle of 30 tablets retails for around $9.
Adults age 50 and older have slightly different nutritional needs than those in the 18-49 age bracket. Seniors tend to absorb less B12 as they age, with the Mayo Clinic recommending supplementation to maintain healthy B12 levels. Seniors also typically require higher doses of vitamin D to maintain bone health. Multivitamins designed for older adults can help cover these needs.
Among seniors’ multivitamins, we like Kirkland Signature Adults 50+ Mature Multi. Like our other adult picks, it contains a wide range of important nutrients — with senior-friendly doses of vitamins B12 and D. The serving size is just one pill per day, and it’s also an affordable option: A bottle of 400 pills retails for about $13, or $0.03 per dose.
If you’re looking for a food-based supplement, MegaFood also makes multivitamins for men and women over 55. These contain nutrients similar to Kirkland Signature, with a few variations: You get slightly less vitamin B12 — and the Multi for Women 55+ omits iron, while the Multi for Men 55+ contains pumpkin seed extract, which MegaFood claims supports a healthy prostate (the science is promising but scant). But be warned that these options are pricier: 60 tablets will run you $25, and the recommended serving is two tablets daily.
Other Multivitamins to Consider
Nature Made’s multivitamins are another good choice for anyone looking for a well-rounded daily tablet that has a third-party stamp of approval. Both the men’s and women’s blends are verified by USP to ensure label accuracy, and the Nature Made Multi for Her was one of 70 tested and approved by ConsumerLab. Both the men’s and women’s formulas earned a 72 out of 100 ranking from Labdoor: Each earned high marks for purity, but also showed some ingredient inconsistencies. (Among other variations, the women’s tablet contained 51 percent more vitamin C than the label claimed, and the men’s tablet contained 175 percent more vitamin B6 than reported. These aren’t dangerous levels or ingredients, but they do indicate a little less precision with formulations.)
Despite its name, Nature Made is synthetic. It’s cheaper than the MegaFood multivitamins, but more than the Kirkland Signature: The women’s Nature Made multi costs 11 cents per one-tablet serving, and the men’s multi costs 10 cents for the same. On the downside, it has more extraneous fillers and binders than the MegaFood options, and contains the artificial sweetener maltodextrin. Neither MegaFood nor Kirkland Signature contain maltodextrin. Regardless, both Nature Made formulas contain 26 of the 27 nutrients deemed essential by the FDA; only potassium is missing.
The difference between the men’s multi and the women’s is minor. The tablet formulated for men doesn’t contain iron and has a little less calcium (162 milligrams compared to 250 milligrams). It also contains three times as much vitamin B12, which feeds neurological function and the formation of red blood cells.
A Guide to Vitamins and Minerals
To help you navigate the buying process regardless of your individual nutritional needs, we’ve provided the following guide with a quick overview of different vitamins and minerals, common food sources, and the most up-to-date recommended daily values for adults (measured in international units, micrograms, milligrams, and grams). Of course, no multivitamin is going to have 100 percent of what you need, so your best bet is to talk to your doctor to find out what you’re lacking, and find a supplement that’s stacked in your favor.
Vitamin A: Found in meat, poultry, dairy, leafy greens, and fruits, Vitamin A is particularly important for maintaining healthy eyesight and a strong immune system. However, too much Vitamin A can lead to nausea, painful bones, and other side effects. To avoid overdose, multivitamin manufacturers generally only provide 50-80% of the recommended daily value in each serving.
- Recommended daily value: 3,000 IU male, 2,300 IU female
Vitamin C: Also known as ascorbic acid, Vitamin C is found most commonly in citrus fruits, though smaller amounts are present in spinach, potatoes, and strawberries. Studies show that contrary to popular belief, Vitamin C does not prevent colds, but it does help the body create collagen, strengthens the immune system, and acts as an antioxidant. Because the overdose limit is so high, manufacturers usually include well over 100% of the recommended daily value. If you’re particularly concerned about supplementing Vitamin C in your diet, check out our review for the Best Vitamin C Supplement here.
- Recommended daily value: 90 mg male, 75 mg female
Vitamin D: Vitamin D, also known as calciferol, strengthens teeth and bones by helping the body to absorb calcium. When taken in combination with calcium over the long term, Vitamin D can help prevent osteoporosis in adults. But be careful not to take more than recommended: overdose can cause nausea or dizziness. Food sources include fatty fish and fortified milk or cereals — and, of course, your body will produce Vitamin D if exposed to sunlight, but the amount produced through sunlight alone rarely meets recommended daily values.
- Recommended daily value: 600 IU
Vitamin E: Vitamin E (AKA tocopherol) serves as an antioxidant and immune booster in the body. It can be found in a wide variety of foods, including vegetable oils and leafy greens. Deficiencies are very rare, but overdosing on Vitamin E supplements can reduce your ability to form clots while bleeding.
- Recommended daily value: 33 IU synthetic, 22 IU natural
Vitamin K: Vitamin K (also known as menadione or phylloquinone) is important for blood clotting and maintaining strong bones. If you are taking a blood thinner, keep your vitamin K intake consistent to ensure your blood can clot properly. Food sources of Vitamin K include cabbage, liver, eggs, milk, and green vegetables.
- Recommended daily value: 120 mcg male, 90 mcg female
Biotin: Biotin helps turn food into energy and can be found in whole grains, egg yolks, soybeans, fish, and organs. It hasn’t proved to be harmful in high doses.
- Recommended daily value: 30 mcg
Choline: Choline helps maintain healthy nerve and brain functions, and metabolizes fats. It can be found in milk, eggs, liver, peanuts, and salmon.
- Recommended daily value: 550 mg male, 425 mg female
Folate: Also known as Vitamin B-9, folacin, and folic acid, this vitamin helps with cell creation and can be found in many foods, including grains, cereals, greens, and fruit juice. Getting enough folate is especially important for pregnant women. If you’re planning on taking prenatal supplements, consider reading our review of the best prenatal vitamins.
- Recommended daily value: 400 mcg
Niacin: Niacin (also known as vitamin B-3 or nicotinic acid) helps maintain digestive, skin, and nerve health. It's important for converting food to energy, and can be found in many foods, including poultry, fish, whole grains, peanuts, and legumes.
- Recommended daily value:16 mg male, 14 mg female
Pantothenic Acid: Also known as vitamin B-5, pantothenic acid helps metabolize food, as well as produce hormones, cholesterol, and neurotransmitters. It’s found in a variety of foods, including chicken, whole grains, avocados, mushrooms, broccoli, and egg yolks.
- Recommended daily value: 5 mg
Riboflavin: Riboflavin (AKA Vitamin B-2) helps metabolize food and maintain healthy skin, blood, and brain functions. It's present in a wide variety of foods, including eggs, leafy greens, enriched grains and cereals.
- Recommended daily value: 1.3 mg male, 1.1 mg female
Thiamin: Thiamin (also called vitamin B-1) helps convert food to energy and maintain healthy nerves, brain, muscles, hair, and skin. It can be found in soymilk, watermelons, ham, brown rice, porkchops, and acorn squash.
- Recommended daily value: 1.2 mg male, 1.1 mg female
Vitamin B-6: Also called pyridoxine, pyridoxal, and pyridoxamine, Vitamin B-6 is critical in brain, immune, and metabolic functions. It's found in poultry, fish, organ meats, starchy vegetables, and non-citrus fruits.
- Recommended daily value: 1.3 mg
Vitamin B-12: Also called cobalamin, Vitamin B-12 is especially important for nerve and blood cell creation. It can be found most commonly in meat, poultry, and fish. Vegans and vegetarians are often at risk for deficiency, and should pay attention to their vitamin B12 intake.
- Recommended daily value: 2.4 mcg
Calcium: Calcium maintains healthy bones, blood pressure, and nerve function. It can be found in many foods, especially dairy products, kale, broccoli, and Chinese cabbage. Multivitamins typically contain less than the daily recommended value for calcium because it’s a bulkier mineral. If you’re especially concerned about your calcium intake, take a look at our review for calcium supplements.
- Recommended daily value: 1,000 mg 19-50 years, 1,200 mg 50-plus
Chromium: Chromium helps maintain healthy blood sugar, and can be found in meat, poultry, fish, eggs, potatoes, nuts, and cheese.
- Recommended daily value: 35 mcg male, 25 mcg female
Copper: Copper is important for red blood cell creation and immune system health. It can be found in liver, shellfish, nuts, beans, and whole-grain foods. Copper is poisonous in large amounts, though overdosing through food or supplement sources is unlikely.
- Recommended daily value: 900 mcg
Iodine: Iodine is important for thyroid and metabolic function. It can be found in seafood, iodized salt, bread, and drinking water.
- Recommended daily value: 150 mcg
Iron: Iron helps the body create red blood cell proteins, hormones, and tissue. It can be found in meat, poultry, seafood, and some vegetables and grains. Vegetarians and pregnant women can be at risk for iron deficient-diets. If you're concerned about your iron intake, check out our iron supplement review.
- Recommended daily value: 8 mg male, female 50-plus, 18 mg female 19-50
Magnesium: Magnesium aids in nerve and muscle function, blood clotting, and strengthening bones. It can be found in green vegetables, legumes, whole-wheat bread, and milk, and yogurt.
- Recommended daily value: 400-420 mg male, 310-320 mg female
Molybdenum: Molybdenum helps maintain nerve health and can be found in legumes, nuts, grains, and milk. Deficiencies are extremely rare.
- Recommended daily value: 45 mcg
Manganese: Manganese helps strengthen bones and metabolize amino acids, carbohydrates, and cholesterol. In some places, manganese is added to drinking water. People with liver damage should be especially careful not to exceed the upper limits for manganese. Foods with manganese include fish, nuts, legumes, and whole grains.
- Recommended daily value: 2.3 mg male, 1.8 mg female
Phosphorus: Phosphorus is abundant in the body, making up 1% of your total weight. It helps maintain healthy teeth and bones, create cells, and metabolize food. It can be found in dairy products, meat, poultry, fish, eggs, green peas, broccoli, liver, potatoes, and almonds.
- Recommended daily value: 700 mg
Potassium: Potassium is important in many functions, from building proteins and muscle, to maintaining a healthy heart and nervous system. It can be found in meat, milk, fruits, vegetables, grains, and legumes. People with kidney issues should avoid eating too many potassium-rich foods.
- Recommended daily value: 4.7 g
Selenium: Selenium acts as an antioxidant and also regulates thyroid activity. It can be found in seafood, organ meats, walnuts, and grains.
- Recommended daily value: 55 mcg
Zinc: Zinc helps with protein and cell creation, and maintains a healthy immune system. It can be found in red meat, poultry, oysters, beans, nuts, and fortified cereals. Vegetarians are at a higher risk for zinc deficiency.
- Recommended daily value: 11 mg male, 8 mg female
With vitamins, more isn’t necessarily better.
Perhaps more important than scouring daily recommended values is keeping an eye on recommended upper limits. ConsumerLabs has a detailed chart that compares recommended daily values with upper limits, but in general, it’s not a good idea to consume excessive doses of any one vitamin or nutrient.
Upper limits for any vitamin vary widely: More than twice the recommended amount of Vitamin A is dangerous, but you can have up to 26 times the recommended daily amount of Vitamin C without experiencing any ill effects.
Price said her research shows a multivitamin probably won’t contain a dangerous amount of vitamins or minerals on its own — and none of our top picks exceed recommended upper limits for any ingredient. But she said taking a multivitamin while supplementing with other vitamins or while consuming fortified foods or beverages could lead to a “superdose” — a vitamin dosage so far over the recommended amount it can lead to problems.
For kids, superdoses can be fatal. Warnings to keep multivitamins containing iron out of children’s reach are there for a reason: Accidental iron consumption is a leading cause of poisoning deaths in children younger than 6. Gummy vitamins can be especially dangerous for kids, since they resemble candy or fruit snacks.
And remember: Most people probably don't need a multivitamin at all.
In our research for the best multivitamin, we kept running into the same question: Do most Americans even need to take a multivitamin?
When we called Dr. Edgar Miller, a professor of medicine at the Johns Hopkins University School of Medicine, he told us he doesn’t recommend that his patients take multivitamins, since several studies have indicated they might do more harm than good: Research has shown high doses of vitamin A seemed to increase the risk of lung cancer, and another study of vitamin E’s effect on prostate cancer was called off after those taking the supplements showed higher cancer rates. Dr. Miller put things pretty plainly: “I hate to advocate for any multivitamin, really. Just getting your vitamins from food is better.”
Even in some cases of nutrient deficiency, a multivitamin might be overkill, Palmer adds. “For most people, they may not be lacking in every single essential vitamin and mineral — it may be just one or two,” she told us. “For example, someone at risk for osteoporosis may want to take calcium; someone battling iron anemia may want to take iron; and a vegetarian may want to take B12.”
Pregnant women, Miller says, are the exception. It’s widely agreed that pregnant women should take a supplement that includes folic acid to support the developing fetal nervous system. (Check out our review on the best prenatal vitamins if you’re expecting.)
Our Multivitamin Review: Summed Up
Keep a food journal for a week. Track everything fueling your body. If your diet lacks nutrients or seems especially imbalanced, try to change it. All four of our experts agree that food is hands-down the best way to consume vitamins and minerals.
Talk to your doctor. If you still suspect your diet is lacking, or if you can’t change what you eat due to dietary restrictions, meet with your doctor to discuss taking a multivitamin. He or she may order a blood test to detect nutritional deficiencies, or make recommendations about dietary modifications.
Get your vitamin D outside. Most vitamins can be found in food, but vitamin D remains a notable exception: Your body endogenously synthesizes vitamin D when ultraviolet rays from the sun hit your skin. Our picks contain vitamin D, but as always, vitamins are best absorbed from natural sources.