Do Multivitamins Actually Do Anything?

Multivitamins are among the most commonly used dietary supplements worldwide. Millions of adults take them daily for general health, energy, longevity, or as "nutritional insurance."

But when you strip away marketing claims and look at current large-scale evidence, the reality is more nuanced. Multivitamins can prevent or correct nutrient deficiencies and may provide some modest cognitive benefits in older adults.

However, they do not provide any additional benefits if you're already eating enough vitamins. This doesn't mean they're worthless; it just means they're used to treat deficiencies rather than provide ergogenic benefits.

Understanding where they help and where they don't will make it easier to decide whether to use them. 

Key Points You Need To Know! About ⅓ of the U.S. population takes multivitamins. Their primary use is to address deficiencies, not cure diseases. While studies vary, long-term daily use is associated with a reduced risk of several major health conditions, such as certain cancers and heart disease.  If you eat a balanced, nutritious diet, there is little reason to add a multivitamin to your regimen.

What Are Multivitamins?

Multivitamin–mineral supplements (MVMS) contain combinations of essential vitamins and minerals, typically formulated to provide 100% or more of the Recommended Dietary Allowance (RDA).

As the National Institutes of Health Office of Dietary Supplements states, multivitamins are designed to help individuals meet micronutrient requirements.

However, they are not designed to help improve performance beyond normal physiological limits. If your diet already provides all the necessary vitamins and minerals, taking a multivitamin won't provide any extra benefit.

What Do Multivitamins Include?

Different brands generally consist of a mixture of vitamins and minerals, including;

• Fat-soluble vitamins (i.e., A, D, E, K)
• Water-soluble vitamins (i.e., B-complex and vitamin C)
• Minerals such as zinc, selenium, iodine, magnesium, and sometimes iron

Some products, like SFS Complete Multivitamins, also include;

• Antioxidants
• Various compounds for immune support 
• Other general health compounds, such as stinging nettle and lutein

Keep in mind that every brand can be slightly different in the exact micronutrients and dosing. 

Do You Need to Take a Multivitamin?

This heavily depends on your specific situation and, more importantly, your diet.

For healthy adults consuming a varied, nutrient-dense diet, recent large-scale research does not show a strong mortality benefit from routine multivitamin use (Loftfield et al., 2024; Lourenço et al., 2025).

One interesting study to consider examined how multivitamins made people feel, regardless of any actual health benefits. Users overwhelmingly reported feeling better, even though there was no meaningful physiological benefit (Paranjpe et al., 2020).

However, the absence of mortality reduction does not equal the absence of benefit, as we'll see below. It means benefits may be population-specific rather than universal.

Older Adults

A 2024 meta-analysis published in the American Journal of Clinical Nutrition found that daily multivitamin use led to modest but statistically significant improvements in global cognitive function (Vyas et al., 2024).

The effect size was not large, but it was consistent across cognitive domains. This suggests multivitamins may support cognitive aging in older populations.

Individuals With Suboptimal Diet Quality

National intake data show persistent micronutrient inadequacies in certain groups, particularly for vitamin D, magnesium, and vitamin A (NIH ODS, 2024). 

Individuals with limited food variety, calorie restriction, or inconsistent dietary patterns may benefit from supplementation to maintain adequacy.

During Pregnancy

Periconceptional folate supplementation significantly reduces the risk of neural tube defects (De-Regil et al., 2015). This remains one of the strongest and most established examples of multivitamin benefits.

During Calorie Restriction

During fat-loss phases, total food intake decreases. Lower intake increases the risk of micronutrient inadequacy. In this context, a multivitamin may help maintain sufficiency.

Do Multivitamins Improve Health or Correct Deficiencies?

Multivitamins have been found to be associated with reduced risk and incidence of several diseases and health conditions. On the other hand, some have shown neutral associations, while a few have had a negative connection.

Further, because multivitamins contain a range of compounds, it's hard to pinpoint which specific compound is responsible for the improvements.

Can Multivitamins Correct Deficiencies?

When deficiencies are present, supplementation improves physiological function. For example:

• Iron corrects iron-deficiency anemia.
• Vitamin B12 restores neurological and hematologic function.
• Vitamin D corrects deficiency-related bone disorders.

These effects are well established.

Multivitamins Effects On Cancer

Multivitamin use and its association with cancer are mixed. Some studies show a decreased risk, while others show a neutral association or even a negative. This is usually associated with iron toxicity.

• Combined supplementation with beta-carotene, alpha-tocopherol, and selenium reduced the incidence of and mortality rate from gastric cancer and the overall mortality rate from cancer by 13% to 21% (Huang et al., 2006). 
• Combined supplementation with vitamin C, vitamin E, beta-carotene, selenium, and zinc reduced the rate of cancer by 31% in men but not in women (Huang et al., 2006).
• Long-term use of multivitamins may substantially reduce risk for colon cancer (Giovannucci et al., 1998; White et al., 1997)
• In a large prevention trial of male physicians, daily multivitamin supplementation modestly but significantly reduced the risk of total cancer (Gaziano et al., 2012).

Heart Disease

• Women taking a multivitamin daily for 3 years had a lower risk of heart disease (Bailey et al., 2015).
• A large Swedish-based study found that daily multivitamin use in women lowered the risk of myocardial infarction (Rautiainen et al., 2010).
• Another large Swedish review found that low-dose multivitamin use results in a lower risk of myocardial infarction in both men and women  (Holmquist et al., 2003)

Multivitamins May Improve Brain, Cognitive Function, and Eye Health

Multivitamin use has shown promising results for various issues regarding brain and eye health, and improving cognition.

• The COSMOS trials demonstrated modest improvements in global cognitive performance among older adults taking multivitamins (Vyas et al., 2024). 
• Daily use of multivitamins has been suggested as a reliable therapy to reduce age-related cataracts (Zhao et al., 2014).
• May reduce the progression of age-related macular degeneration (Evans & Lawrenson, 2012)

Mortality and Cardiovascular Outcomes

In terms of broader benefits or evidence that multivitamins reduce mortality, there are no studies supporting this claim.

• Recent data suggest that multivitamin use is not associated with a significant reduction in all-cause mortality (Loftfield et al., 2024). 
• No significant reduction in cardiovascular events was observed in large population analyses (Lourenço et al., 2025).

These findings indicate that multivitamins do not function as broad disease-prevention tools in well-nourished adults, but sleeping can!

Support Performance And Muscle Health

While this is an auxiliary benefit, numerous studies have shown that deficiencies in several vitamins are associated with a decrease in performance. 

• Muscle fatigue
• Possible improve recovery
• Blood and circulatory health

Our article here goes into this in much more detail!

This is why, if you are highly active and know you're getting all of your nutrients, low-dose vitamin supplementation can possibly benefit you.

Can Your Body Absorb All the Vitamins in a Multivitamin?

The body regulates absorption based on need. If nutrient status is adequate, absorption efficiency may decrease, and excess of many water-soluble vitamins is excreted (NIH ODS, 2024).

This is why high-dose supplementation rarely provides additional benefit in individuals who are already sufficiently supplemented.

While we're not doctors, we suggest most people take half a dose of most multivitamins. This is especially true when you're taking them as "vitamin insurance".

What Are Water-Soluble Vitamins?

• Vitamin C
• B-complex vitamins (B1, B2, B3, B5, B6, B7, B9, B12)

How They're Absorbed

Water-soluble vitamins are absorbed directly into the bloodstream through the small intestine.

• They use specific transport proteins. 
• They do not require dietary fat for absorption.
• They enter portal circulation and go directly to the liver.

Because they dissolve in water:

• Excess amounts are generally excreted in urine.
• They are not stored extensively (except for B12, which is stored in the liver).

Which are more prone to Absorption Issues?

Certain water-soluble vitamins are especially vulnerable:

• Vitamin B12 – Absorption declines with aging, gastric surgery, low stomach acid, or certain medications.
• Folate (B9) – Can be impaired by alcohol use or intestinal disorders.
• Vitamin C – High doses have diminishing absorption efficiency (saturable transport).

In general, water-soluble vitamins are less likely to accumulate to toxic levels but can be more sensitive to gastrointestinal health.

What Are Fat-Soluble Vitamins?

• Vitamin A
• Vitamin D
• Vitamin E
• Vitamin K

How They're Absorbed

Fat-soluble vitamins require dietary fat and normal digestive function for proper absorption. This means;  

• They require adequate bile production.
• They rely on pancreatic enzymes.
• They are stored in the liver and adipose tissues.

Which are more prone to Poor Absorption?

Fat-soluble vitamins are generally more prone to malabsorption in certain conditions, such as low-fat diets or liver disease

Among them:

• Vitamin D deficiency is extremely common globally.
• Vitamin A absorption can be compromised in fat-malabsorption syndromes.
• Vitamin K levels can be affected by long-term antibiotic use (due to disruption of the gut microbiota).

Because fat-soluble vitamins are stored, chronic malabsorption may not show symptoms immediately, but long-term deficiency can develop.

Final Say On Multivitamins: Should You Take Them? 

Multivitamins are not magic, but they also aren't useless. Their effectiveness depends on baseline nutritional status; they counteract sedentary behavior, chronic metabolic dysfunction, and a consistently poor-quality diet.

They also don't replace real food and shouldn't be seen as an alternative. However, they can serve as a safeguard in populations at risk of micronutrient inadequacy.

If your diet consistently meets micronutrient needs, the benefit is likely modest.

However, if you are at risk of inadequacy or want insurance, check out our SFS Complete Multivitamin with:

• Full spectrum of vitamins and minerals
• Prostate-supportive herbs and nutrients
• Immune system support and antioxidants

FAQ: Do Multivitamins Actually Work?

1. Why are multivitamin doses so high?

The RDAs are designed to prevent deficiency, not necessarily optimize health. Some people may benefit from eating a higher amount than what the RDA prescribes. Manufacturers also account for absorption inefficiencies and nutrient loss over time.

It's also important to note that those numbers can sound scarier than they are. A vitamin might say it has "500%" more than the RDA. This means 5x as much. So if the RDA was 100IU, it provides 500IU

2. Can I take a half-serving of a multivitamin?

Yes. If your diet already covers most micronutrients, taking half a serving still provides nutritional "insurance" without unnecessarily high doses. Many multivitamins significantly exceed daily requirements, so a reduced serving is often sufficient for general health.

3. Can your body absorb everything in a multivitamin?

No. Absorption depends on the nutrient form, digestive health, and interactions between minerals. Water-soluble vitamins have limited absorption capacity, and some minerals compete for uptake. Taking fat-soluble vitamins with food improves absorption.

4. Do multivitamins prevent disease?

In healthy adults, multivitamins have not consistently been shown to prevent heart disease or cancer. Their primary benefit is correcting or preventing nutrient deficiencies, particularly in people with restricted diets or increased needs.

References

1. Bailey, R. L., Fakhouri, T. H., Park, Y., Dwyer, J. T., Thomas, P. R., Gahche, J. J., Miller, P. E., Dodd, K. W., Sempos, C. T., & Murray, D. M. (2015). Multivitamin-mineral use is associated with reduced risk of cardiovascular disease mortality among women in the United States. The Journal of nutrition, 145(3), 572–578. https://doi.org/10.3945/jn.114.204743
2. Evans, J. R., & Lawrenson, J. G. (2012). Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. The Cochrane database of systematic reviews, 11, CD000254. https://doi.org/10.1002/14651858.CD000254.pub3
3. Gaziano, J. M., Sesso, H. D., Christen, W. G., Bubes, V., Smith, J. P., MacFadyen, J., Schvartz, M., Manson, J. E., Glynn, R. J., & Buring, J. E. (2012). Multivitamins in the prevention of cancer in men: the Physicians' Health Study II randomized controlled trial. JAMA, 308(18), 1871–1880. https://doi.org/10.1001/jama.2012.14641
4. Giovannucci, E., Stampfer, M. J., Colditz, G. A., Hunter, D. J., Fuchs, C., Rosner, B. A., Speizer, F. E., & Willett, W. C. (1998). Multivitamin use, folate, and colon cancer in women in the Nurses' Health Study. Annals of internal medicine, 129(7), 517–524. https://doi.org/10.7326/0003-4819-129-7-199810010-00002
5. Huang, H. Y., Caballero, B., Chang, S., Alberg, A. J., Semba, R. D., Schneyer, C. R., Wilson, R. F., Cheng, T. Y., Vassy, J., Prokopowicz, G., Barnes, G. J., 2nd, & Bass, E. B. (2006). The efficacy and safety of multivitamin and mineral supplement use to prevent cancer and chronic disease in adults: a systematic review for a National Institutes of Health state-of-the-science conference. Annals of internal medicine, 145(5), 372–385. https://doi.org/10.7326/0003-4819-145-5-200609050-00135
6. Loftfield, E., et al. (2024). Multivitamin use and mortality risk in 3 prospective U.S. cohorts. JAMA Network Open, 7(6), e2418723. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2820369
7. Lourenço, R., et al. (2025). Vitamin–mineral supplement use and risk of cardiovascular events and mortality. European Journal of Nutrition. https://link.springer.com/article/10.1007/s00394-025-03593-1
8. National Institutes of Health Office of Dietary Supplements. (2024). Multivitamin/mineral supplements: Health professional fact sheet. https://ods.od.nih.gov/factsheets/MVMS-HealthProfessional/
9. Paranjpe, M. D., Chin, A. C., Paranjpe, I., Reid, N. J., Duy, P. Q., Wang, J. K., O'Hagan, R., Arzani, A., Haghdel, A., Lim, C. C., Orhurhu, V., Urits, I., Ngo, A. L., Glicksberg, B. S., Hall, K. T., Mehta, D., Cooper, R. S., & Nadkarni, G. N. (2020). Self-reported health without clinically measurable benefits among adult users of multivitamin and multimineral supplements: a cross-sectional study. BMJ open, 10(11), e039119. https://doi.org/10.1136/bmjopen-2020-039119
10. Rautiainen, S., Akesson, A., Levitan, E. B., Morgenstern, R., Mittleman, M. A., & Wolk, A. (2010). Multivitamin use and the risk of myocardial infarction: a population-based cohort of Swedish women. The American journal of clinical nutrition, 92(5), 1251–1256. https://doi.org/10.3945/ajcn.2010.29371
11. U.S. Preventive Services Task Force. (2022). Vitamin, mineral, and multivitamin supplementation to prevent cardiovascular disease and cancer. JAMA, 327(23), 2326–2333. https://jamanetwork.com/journals/jama/fullarticle/2793446
12. Zhao, L. Q., Li, L. M., Zhu, H., & The Epidemiological Evidence-Based Eye Disease Study Research Group, E. Y. (2014). The effect of multivitamin/mineral supplements on age-related cataracts: a systematic review and meta-analysis. Nutrients, 6(3), 931–949. https://doi.org/10.3390/nu6030931
13. Vyas, C. M., et al. (2024). Effect of multivitamin–mineral supplementation on cognitive function: COSMOS randomized trials. The American Journal of Clinical Nutrition, 119(1), 110–120. https://ajcn.nutrition.org/article/S0002-9165(23)66342-7/fulltext
14. White, E., Shannon, J. S., & Patterson, R. E. (1997). Relationship between vitamin and calcium supplement use and colon cancer. Cancer epidemiology, biomarkers & prevention: a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 6(10), 769–774 https://pubmed.ncbi.nlm.nih.gov/9332757/