Should You Take Multivitamins?

Approximately one third of American adults pop a multivitamin each morning, hoping to boost their health, fill nutritional gaps, or simply gain peace of mind. But here’s the surprising truth: despite their popularity and widespread use, the latest research suggests that for most healthy adults, multivitamins may not deliver the benefits you expect.​

A groundbreaking 2024 study analysing data from nearly 400,000 healthy adults followed for over 20 years found no association between regular multivitamin use and lower risk of death. The research showed no protective effects against cancer, heart disease, or stroke either. Even more concerning, users actually exhibited a 4% higher mortality risk in the initial years of follow up.​

Before you toss your bottle in the trash or rush to buy one, though, understand this: the multivitamin question isn’t black and white. While healthy adults eating balanced diets may not need them, certain populations can genuinely benefit from supplementation. Let’s break down what science really says about multivitamins and who should consider taking them.

What Does the Research Really Say About Multivitamins?

The scientific evidence on multivitamins has been accumulating for years, and the consensus is becoming clearer.

No Longevity Benefits for Healthy Adults

The U.S. Preventive Services Task Force analysed 84 studies involving nearly 700,000 people and concluded there’s insufficient evidence to support any benefit from vitamin and mineral supplements for preventing cancer or cardiovascular disease. For the average healthy person who isn’t deficient, giving yourself more vitamins and minerals than you need likely doesn’t benefit your overall health.​

Multiple large scale studies have reached similar conclusions. The 2024 National Cancer Institute study tracked participants for more than 20 years and found that people taking daily multivitamins did not have a lower risk of death from any cause compared to those taking no multivitamins. There were also no differences in mortality from cancer, heart disease, or cerebrovascular diseases.​

Mixed Results on Specific Health Outcomes

While multivitamins don’t appear to extend lifespan or prevent major diseases in healthy adults, research on other outcomes shows mixed results.​

The Physicians’ Health Study II found modest reductions in cancer and cataracts among men taking multivitamins, but no protective effect against cardiovascular disease or declining mental function. Some studies suggest potential cardiovascular benefits for long term users, while others report adverse associations for mortality among older women and prostate cancer mortality among men.​

These varying results across observational studies may be explained by differences in multivitamin composition, confounding factors, or the health status of participants.​

The One Area Where Multivitamins May Help: Cognitive Function in Older Adults

While multivitamins may not extend your life, emerging research suggests they might help protect your memory as you age.

Memory Benefits in Seniors

A 2023 study of more than 3,500 adults over age 60 found that taking a daily multivitamin improved memory performance. By the end of the first year, participants taking multivitamins performed better on immediate recall tests than those taking a placebo.​

The researchers estimated that the multivitamin intervention improved memory performance by the equivalent of 3.1 years of age related memory change. This improvement was sustained over the three year study period.​

Stronger Effects for Those with Cardiovascular Disease

Notably, the memory benefits were more pronounced in participants with underlying cardiovascular disease. There’s evidence that people with cardiovascular disease may have lower micronutrient levels that multivitamins may correct, though researchers don’t fully understand why the effect is stronger in this group.​

A 2024 follow up trial involving about 5,000 older adults confirmed these findings, showing that multivitamin use led to enhanced memory and delayed cognitive aging by two years. In the same trial, multivitamin takers were also less likely to get lung cancer, though no benefits were observed for other cancers or heart disease.​

While these findings are promising, it’s important to note that taking a multivitamin should not be viewed as a substitute for eating a healthy diet or practising other healthy lifestyle behaviours.​

Who Actually Needs Multivitamins?

While the average healthy adult eating a balanced diet likely doesn’t need a multivitamin, certain populations can genuinely benefit from supplementation.

Older Adults

As we age, our ability to absorb nutrients from food decreases, and our energy needs change, leading us to eat less. Older adults often develop deficiencies in specific nutrients.​

Vitamin B12 absorption decreases with age, and older adults may need more calcium and vitamin D. For people over 65, a multivitamin can help fill these gaps, especially given the emerging evidence for cognitive benefits.​

Pregnant Women and Those Planning Pregnancy

Pregnant women have significantly higher nutrient needs and are advised to take multivitamins or prenatal vitamins.​

Folic acid is particularly critical. Taking 400 micrograms of folic acid daily before conception and during the first 12 weeks of pregnancy can help prevent serious neural tube defects like spina bifida. These defects occur within the first 28 days of pregnancy, often before a woman even knows she’s pregnant.​

The CDC recommends that all women of childbearing age take folic acid every day since half of all pregnancies are unplanned. Pregnant women also need adequate iron to prevent anaemia and support the baby’s growth.​

Vegetarians and Vegans

People following plant based diets are at higher risk of certain deficiencies. Vitamin B12 is found primarily in animal foods, making vegans and strict vegetarians particularly vulnerable to deficiency.​

They may also lack adequate calcium, zinc, iron, vitamin D, and omega 3 fatty acids. For these individuals, taking a multivitamin can help ensure they meet their nutritional needs.​

People with Nutrient Absorption Issues

Certain conditions and situations impair the body’s ability to absorb nutrients from food.​

Those who may benefit from multivitamins include people who have undergone bariatric surgery, have gastrointestinal conditions that affect absorption, follow very low calorie diets, have chronic kidney disease, or take certain medications that interfere with nutrient absorption.​

Additionally, people with food insecurity who have limited access to healthy food may have better health outcomes when taking multivitamins.​

Those with Documented Deficiencies

If you have a diagnosed vitamin or mineral deficiency, supplementation makes sense. However, it’s often best to supplement with that specific nutrient rather than a broad multivitamin.​

Common deficiencies include vitamin D (especially in winter months or for people with limited sun exposure), vitamin B12 (particularly in older adults and vegans), and iron (in people with anaemia).​

Why Food Is Better Than Supplements

Even if you fall into a category that might benefit from multivitamins, food should always be your primary source of nutrition.

The Food Matrix Advantage

When you eat a whole food, you’re not consuming isolated nutrients you’re eating all of the food’s components working together. Vitamins, minerals, fibre, fats, protein, and beneficial plant compounds are bound together, interacting to form what’s called the food matrix.​

These interactions within the food matrix enhance nutrient absorption in ways that isolated supplements cannot replicate. Research shows that diet patterns emphasising whole foods yield more substantial health benefits than single nutrients alone.​

Nutrients from food are associated with a lower risk of mortality than nutrients from supplements.​

What Supplements Lack

A multivitamin may contain all the zinc or vitamin E you need, but it lacks the other compounds found in whole foods. Supplements lack fibre, antioxidants, phytonutrients, and the synergistic combination of micronutrients that work together in food.​

Consider a whole orange versus a vitamin C supplement. Both contain vitamin C, but the orange also provides 3 grams of fibre, vitamin A, calcium, and 1 gram of protein. These additional nutrients work synergistically to enhance absorption and provide health benefits that the isolated supplement cannot match.​

Vitamins and minerals are most potent when they come from food, accompanied by hundreds of carotenoids, flavonoids, minerals, and antioxidants that aren’t in most supplements. Plus, food tastes better and is often less expensive than supplements.​

Better Absorption from Real Food

The 2015 to 2020 Dietary Guidelines for Americans recommend getting nutrition from whole foods versus supplements. This recommendation aims to increase the consumption of fruits, vegetables, and dairy food groups.​

These food groups contain fibre, antioxidants, and micronutrients that work synergistically to enhance absorption, allowing the body to use nutrients more easily. This same effect is not seen in supplements because they lack the micronutrient combination found in whole foods.​

The Potential Risks of Multivitamins

While multivitamins are generally safe for most people when taken as directed, they’re not without potential risks.

Risk of Excess Intake

The amount of vitamins and nutrients in multivitamins generally does not exceed the recommended daily allowance. However, problems can occur if single vitamins are taken in addition to multivitamins, leading to excess intake.​

The vitamins and micronutrients most commonly associated with excess intake include vitamin A, vitamin C, niacin, iron, and zinc. For vitamins to cause side effects, intake typically needs to exceed the recommended daily allowance several fold.​

Specific Vitamin Toxicity Concerns

Fat soluble vitamins (A, D, E, and K) can accumulate in the body’s tissues, potentially leading to toxicity. Unlike water soluble vitamins, which are expelled through urine when taken in excess, fat soluble vitamins can build up over time.​

Vitamin A toxicity can cause hepatotoxic effects, visual changes, hair and skin changes, and a potential increased risk of hip fracture. While natural beta carotene from food can protect against cancer, beta carotene supplements may increase the likelihood of lung cancer and heart disease among smokers.​

Vitamin D toxicity leads to hypercalcemia (high blood calcium levels), which can cause nausea, vomiting, weakness, frequent urination, bone pain, and kidney problems. Taking megadoses of vitamin D more than 50,000 IU daily over long periods can even lead to death.​

Vitamin E in excess can cause antiplatelet effects, potentially increasing bleeding risk, especially when combined with medications like aspirin or warfarin.​

The tolerable upper limit for vitamin D is 4,000 IU daily for most adults, and for vitamin A is 3,000 RAE per day.​

Iron Overload Concerns

Many multivitamins include iron, which can result in iron overload for people who don’t need extra iron. Iron overload heightens risks of cardiovascular disease, diabetes, and dementia.​

One study found that calcium supplements can increase the risk of heart attack, prompting doctors to recommend that people with a high risk of heart disease get their calcium through diet rather than supplements.​

Drug Interactions

Common interactions occur between vitamins and medications. Vitamin E and aspirin together lead to increased antithrombotic effects, while vitamin E and warfarin increase the likelihood of bleeding.​

Always inform your healthcare provider about any supplements you’re taking to avoid potentially dangerous interactions.

Making the Right Decision for You

So should you take a multivitamin? The answer depends on your individual circumstances.

When Multivitamins Make Sense

Consider taking a multivitamin if you are over 65 years old, pregnant or planning to become pregnant, following a vegetarian or vegan diet, have undergone bariatric surgery or have absorption issues, have documented nutrient deficiencies, experience chronic stress affecting your diet, or have limited access to nutritious foods.​

Choosing a Quality Multivitamin

If you decide to take a multivitamin, choose wisely. Look for a well known brand that’s been around for a long time and is likely to have been carefully tested. Check that it contains B vitamins (especially folate), vitamin D, and appropriate levels of minerals.​

Make sure the multivitamin doesn’t exceed 100% of the daily value for most nutrients unless specifically recommended by your healthcare provider. Avoid megadoses, particularly of vitamins A and E, which may actually be harmful.​

Talk to Your Healthcare Provider

Before starting any supplement regimen, consult with your doctor or a registered dietitian. They can assess whether you have any deficiencies through blood tests and recommend the appropriate supplementation if needed.​

Ask yourself why you’re considering a multivitamin. Could you have a vitamin deficiency? How’s your diet? Do you eat as healthily as you could?​

Your healthcare provider can help you determine if you really need to take a multivitamin or if dietary changes would be more beneficial.​

Focus on Diet First

For most people, the best approach is to improve the diet before turning to supplements. A healthy, well balanced diet typically provides enough essential vitamins and minerals without the need for supplementation.​

Following a diet with plenty of fruits, vegetables, whole grains, lean proteins, and healthy fats will usually provide sufficient vitamins and minerals. This approach gives you the full benefit of the food matrix, fibre, and phytonutrients that supplements simply cannot replicate.​

The Bottom Line

Multivitamins are not a ticket to optimal health. For most healthy adults eating balanced diets, the scientific evidence does not support taking a daily multivitamin to prevent disease or extend lifespan.​

However, specific populations including older adults (especially for cognitive benefits), pregnant women, vegetarians and vegans, and those with documented deficiencies or absorption issues may genuinely benefit from multivitamin supplementation.​

If you decide to take a multivitamin, choose a quality product, avoid megadoses, and remember that supplements cannot substitute for a healthy diet and lifestyle. The vitamins and minerals you get from a colourful plate of fruits, vegetables, whole grains, and lean proteins will always be more powerful than those from a pill.​

The most important takeaway? Don’t rely on a multivitamin to compensate for poor eating habits. Instead, invest your time and money in building a nutrient rich diet that nourishes your body from the inside out. If you suspect you need supplementation, work with your healthcare provider to identify specific deficiencies and create a personalised plan that’s right for your unique health needs