Multivitamins: Benefits, Risks, and How to Use Them Wisely

Published January 2, 2026

^{Written by Kara Jensen, PharmD, BCPS; 2025-2026 ISMP Safe Medication Management Fellow, supported by the US Army}

Multivitamins are considered a dietary supplement. They are over-the-counter (OTC) products that contain one or more dietary ingredients, such as:

• vitamins (e.g., A, C, E);
• minerals (e.g., calcium, potassium, iron);
• herbs (e.g., turmeric, ginger, echinacea), and/or
• amino acids(e.g., leucine, lysine, threonine).

According to the Centers for Disease Control and Prevention (CDC), more than half (57.6%) of US adults reported using at least one dietary supplement in the past 30 days, with most being multivitamins.¹ Use is also higher among women than men and increases with age.

Understanding Dietary Supplements Versus Medicines

Imagine a multivitamin as a nutritional "safety net,” it is there to catch you if your diet falls short. Multivitamins are designed to supplement your diet. Think of it as adding a little extra insurance to make sure you are getting everything your body needs to function properly.

Medicines, on the other hand, are like targeted missiles designed to address a specific health problem. They are intended to treat, cure, or prevent disease through their actions in the body. Medicines undergo rigorous approvals through the US Food and Drug Administration (FDA) to prove they are safe and effective.

Dietary supplements, on the other hand, are regulated as foods, not medicines, and do not require pre-approval before being sold. Manufacturers are responsible for making sure the product is safe and has an appropriate label, but the FDA typically intervenes only after a product is on the market.

Common Ingredients in Multivitamins

Most multivitamins contain a mix of essential vitamins, such as A, B, C, D, E, and K, and minerals like calcium, iron, magnesium, zinc, and selenium. Not all multivitamins contain the same ingredients or amounts. For example, some include iron, while others are iron-free. The amounts of nutrients can vary widely by brand or product type.

Vitamins A, C, and E are antioxidants which may help protect against damage that can lead to cancer, inflammation, and heart disease.² For example, vitamin D supports bone health, and vitamin K helps form blood clots and also supports strongbones.²

Fat-Soluble Versus Water-Soluble Vitamins

Vitamins A, D, E, and K are fat-soluble, meaning they are stored in body fat and the liver. Taking too much can result in high levels of vitamins within the body that can lead to serious health problems.

Vitamins B and C are water-soluble, so any excess amounts of these vitamins pass through the body and out in your urine. However, this does not mean “more is better” because large doses can still cause side effects (for example, high levels of vitamin C can cause stomach upset).

Pros of Taking a Multivitamin

For people whose diets may be lacking key nutrients, such as those with restricted diets, food allergies, medical conditions, or increased nutritional needs, a daily multivitamin can help fill nutrient gaps and support overall health. Many vitamins and minerals play important roles in immunity, bone strength, energy metabolism, and general wellness. For those who find it hard to eat a variety of foods every day, multivitamins offer a simple way to ensure consistent intake of essential nutrients.

Cons and Cautions

On the downside, not all multivitamins are created equal. Because supplements are not evaluated for effectiveness before reaching store shelves, quality and labeling accuracy can vary.

Taking unnecessary supplements can lead to excess nutrients, potential drug interactions, or even other health issues (as described earlier with fat-soluble vitamins). The FDA warns that supplements can interact with medicines, affect laboratory results, or pose risks during surgery. For example, people who are taking warfarin, a blood thinner, should be aware that vitamin K may interfere with how the medicine works and can increase the risk for blood clots.

There are some studies that show no improvement in health outcomes with the use ofmultivitamins.³ So, relying on a supplement instead of eating foods containing these nutrients may give a false sense of security.

Here’s what you can do: If you choose to take a multivitamin, treat it as a complement, not a replacement, for a healthy diet. Consider the following recommendations when selecting and using a multivitamin.

• Ask your doctor or pharmacist if a multivitamin is right for you.
• Ask your doctor or pharmacist if there are any vitamins, minerals, or other ingredients that you should avoid in a multivitamin.
• Read product labels carefully so you know what is in the product before you purchase it. If you have trouble understanding what the label says, ask your pharmacist for help. Be sure to tell the pharmacist if your doctor told you to avoid certain ingredients.
• Avoid exceeding100% of the recommended daily value unless instructed by your doctor.
• Talk with your pharmacist or healthcare provider before starting any supplement, especially if you take prescription medicines or have a chronic medical condition.
• Take the multivitamin as stated on the label; do not take extra doses.

Good nutrition starts with food first - fruits, vegetables, lean proteins, wholegrains, and healthy fats. Supplements can help fill in gaps, but they do not replace the fundamentals of healthy eating.

References

1. Villarroel MA, Blackwell DL, Vahratian A. Health Insurance Coverage Among Adults Aged 65and Over: Early 2020. NCHS Data Brief, no 399. National Center for HealthStatistics. Published February 2021. Accessed November 19, 2025.
2. National Institutes of Health, Office of Dietary Supplements. Dietary supplements: what you need to know. NIH website. Updated January 4, 2023. Accessed November 19, 2025.
3. National Institutes of Health. For healthy adults, taking multivitamins daily is not associated with lower risk of death. News Release. NIH website. Published June 26, 2024. Accessed November 19, 2025.

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