What Is a Multivitamin? (Benefits, Usage & Side Effects)

Benedict Ang, CPT, PN1-NC
Published by Benedict Ang, CPT, PN1-NC | Staff Writer & Senior Coach
Last updated: March 11, 2024
Our content is meticulously researched and reviewed by an expert team of fact checkers and medical professionals. They ensure accuracy, relevance, and timeliness using the latest reputable sources, which are cited within the text and listed at the end of the article. Before publication and upon significant updates, we confirm factual accuracy, committed to providing readers with well-informed content. Learn more.

While multivitamins are always a hot topic among my clients, it's crucial to understand what they really are and how they can fit into our diets — if they're needed at all.

Given the overwhelming variety of multivitamin supplements available, I've conducted thorough research to figure out how to assess their true value and effectiveness.

Let's dive right in.

Quick Summary

  • Multivitamins combine various vitamins and minerals to supplement nutrition and are particularly focused on nutrients like iron, magnesium, calcium, and various vitamins.
  • They increase nutrition intake, help prevent chronic diseases, and can improve brain function and mood.
  • A study found that men taking multivitamins had a 31% lower risk of cancer, showcasing their potential impact on health.
  • In my opinion, while multivitamins are convenient, a diet rich in whole foods offers a more comprehensive approach to nutrition and health.

What Are Multivitamins (And What Do They Contain)?

There are different set of pills and capsules that are multivitamins

Multivitamins, blending various vitamins and minerals, are a hot topic in the U.S., especially about vitamin D, folic acid, and vitamin A. Folks dive into their benefits, uses, and side effects.

Loads of multivitamins flood the market.

But here's the catch: the FDA doesn't tightly regulate them. So, there's no one-size-fits-all standard, meaning the nutrients in these multivitamins can differ wildly between brands and products.

Most multivitamins contain:

Additionally, certain multivitamins also contain some herbal ingredients or nutrients, such as friendly bacteria, amino acids, fatty acids, or ginseng.

Health Benefits Of Taking Multivitamins

stethoscope on a heart squishy

The benefits of taking multivitamins compared to single individual vitamins include:

Increased Nutritional Intake

Some people cannot or do not meet their food needs due to poor nutrition or some medical conditions. According to a study found on the National Institute of Health (NIH) website, taking multivitamins can help fill these nutritional gaps [1].

Chronic Disease Prevention

Research on multivitamins and chronic diseases gives mixed signals.

Most studies agree: while vitamins and minerals boost overall health, they don't directly slash the risk of chronic diseases like cancer or heart disease.

One study found on the NIH website, with 47,289 participants across five trials, found men taking multivitamins had a 31% lower cancer risk, but it didn't help women [2].

Another NIH study noted that women on multivitamins for over three years had a reduced risk of heart disease and heart attacks [3].

Other Benefits

woman in gym clothes giving a thumbs up outdoors

Multivitamins could boost brain function, mood, and memory, particularly in older adults.

Research shows a clear link between poor nutrition and bad moods. According to ScienceDirect, using multivitamins to tackle nutrition gaps might lessen depression and anxiety symptoms [4].

Plus, antioxidant-rich vitamins and minerals may slow down diseases leading to blindness.

Also Read: How Much of The Multivitamin is Absorbed

“Millions of Americans today are taking dietary supplements, practicing yoga, and integrating other natural therapies into their lives. These are all preventive measures that will keep them out of the doctor's office and drive down the costs of treating serious problems like heart disease and diabetes.”

- Andrew Weil, American Scientist

Can Multivitamins Be Harmful?

High doses of some vitamins can be harmful, so don't mix them with your daily multivitamin.

Remember, overdoing dietary supplements, especially nutrients like zinc, niacin, folic acid, and vitamins A, D, E, and K, can be toxic.

According to the NIH, pregnant women should watch their vitamin A; too much increases the risk of birth defects [5].

Smokers should steer clear of multivitamins with high beta-carotene or vitamin A, which are linked to increased lung cancer risk.

Too much iron might mess with zinc absorption. If your diet's already nutrient-rich, go easy on multivitamins to avoid overloading your daily intake.

Who Should Take Multivitamins?

hand view of a person offering a white pill and glass of water

Vitamins are key for our health. While a balanced diet usually does the trick, some people might struggle to get all the nutrients they need.

That's where multivitamins step in, patching up those tiny yet vital nutritional gaps and warding off symptoms of low intake.

These circumstances include:

  • Age – our bodies find it harder to absorb some essential nutrients as we get older
  • Allergies or intolerances – difficulty absorbing certain nutrients
  • Vegetarianism and veganism – these diets could be missing certain nutrients that are mainly found in animal products
  • Pregnancy and breast-feeding – pregnancy increases your body's need for certain nutrients, such as iron and folate

Taking multivitamins with other medications or dietary supplements can cause drug interactions or affect how medicines work in your body. Ask a doctor to provide medical advice on whether it is safe to use multivitamins if you are on any other medication.

Related Articles:

Comparison with Whole Foods

From my own journey, I've learned that whole foods really do trump multivitamins. When I focused on getting my nutrients from a variety of whole foods, I noticed a significant improvement in my energy levels and overall health.

Unlike isolated vitamins in supplements, whole foods offer a complex mix of compounds that work together to enhance nutrient absorption and effectiveness. It's not just about the individual nutrients; it's the synergy among them that makes the difference.

Plus, whole foods, loaded with fiber and other goodies, are great for digestion, blood sugar balance, and warding off chronic diseases.

Sure, multivitamins are handy, but whole foods deliver a full-package deal for nutrition, ensuring overall health with their nutrient and bioactive mix.


What Happens if I Overdose on Multivitamins?

If you overdose on multivitamins, the side effects can lead to severe complications and, in rare circumstances, even death. These side effects include headaches, nausea, stomach cramps, diarrhea, and vomiting.

Do Multivitamins Cause Weight Gain?

Multivitamins don't make you gain weight, as they hardly include any calories. On the other hand,  multivitamins containing B complex may increase the appetite and trigger obesity.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4109789/
  2. https://pubmed.ncbi.nlm.nih.gov/16880453/
  3. https://pubmed.ncbi.nlm.nih.gov/25733474/
  4. https://www.sciencedirect.com/science/article/pii/S2667242121000257
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6470929/
Was this article helpful?

About The Author

Benedict Ang, CPT, PN1-NC
Staff Writer & Senior Coach
Benedict Ang, CPT, PN1-NC is an ex-National Soccer player turned MMA and Kickboxing champion, with ACE CPT and PN1-NC certifications. His advice is rooted in education and experience, ensuring that readers receive scientific and battle-tested insights. His mission is to empower his clients and readers to realize their potential and become the best versions of themselves.
Learn more about our editorial policy
Dr. Harshi Dhingra, MBBS, MD is a published peer-reviewed author and renowned physician from India with over a decade of experience. With her MBBS from Bharati Vidyapeeth and an MD from Rajiv Gandhi University, she actively ensures the accuracy of online dietary supplement and medical information by reviewing and fact-checking health publications.
Learn more about our editorial policy
Dr. Kristy June Dayanan, BS, MD is an author with a BS degree from University of the Philippines and an MD from University of Perpetual Help System. Her ability to simplify medical science complexities and dietary supplement jargon for the average reader makes her a valued medical fact checker and reviewer.
Learn more about our editorial policy

You May Also Like

Your guide to fenugreek and testosterone
By James Cunningham, BSc, CPT 6 days ago
Does Fenugreek Increase Testosterone Levels? (Science-Based)
Jogging in place
By Benedict Ang, CPT, PN1-NC 26 days ago
Is Running in Place Effective? (What You Should Know)
A woman pouring supplements on her hand and a woman measuring her waist
By Dr. Harshi Dhingra, MBBS, MD 26 days ago
How Do Carb Blockers Work? (Are They Really Effective?)
A couple working out together
By James Cunningham, BSc, CPT 26 days ago
Working Out On An Empty Stomach (Benefits & Side Effects)
A meal full of cereals and healthy foods
By Benedict Ang, CPT, PN1-NC 26 days ago
What is Vitamin G? (Should You Be Taking it)
your guide to drinking protein shake before sleep
By James Cunningham, BSc, CPT 26 days ago
Drinking a Protein Shake Before Bed (Should You Do It)

Write a Reply or Comment

Your email address will not be published. Required fields are marked *

Our scoring system is the result of objective testing data and subjective expert analysis by a team of fitness coaches and medical experts. Our scoring factors are weighted based on importance. For more information, see our product review guidelines.