Get 60% Off The Best Tips to Slow Aging
Supplements & Ingredients

12 Major Dangers of Multivitamin Supplements (Reasons I Quit)

Photo of author



10 Minutes

Affiliate Disclosure: This post contains affiliate links, which means Outliyr LLC gets a small commission if you buy (at no cost to you). Thanks for your support!

Multivitamins Dangers Alternatives Ftd
Multivitamins Dangers Alternatives Ftd

Any conversation about the most important supplements generally includes, at minimum, a mention of multivitamins.

Proponents tout these products as a solid replacement for the nutrients you’d get from consuming a diet rich in whole foods.

Enjoying delicious junk foods and satisfying all nutritional requirements with a few daily pills… what could be better?

Enter any supplement shop worldwide, and you’re virtually guaranteed to find their shelves stocked with multivitamin products.

According to the stats, much of the world takes them.

Your doctor, professional nutritionist, or favorite Instagram influencer may even recommend a particular brand.

So surely they’re critical, right?

In this article, we’re leveling the playing field and discussing the dark side of multivitamin supplements. Including the risks, dangers, side effects, and reasons I switched over to better alternatives many years ago.

Of course, this is for entertainment purposes only. Do your own research and consult your healthcare professional before making any changes to your lifestyle or substance regimen.

Everyone Uses Them

Since the 1940s, fish oil, vitamin D, probiotics, and multivitamins have flown off the shelves faster than any other ingredients.

Every year, $8 billion of the supplement industry goes specifically to multivitamin-related products. And one-third of American adults use multivitamins [R].

Plus, 1,000 new supplement products are being added each year too!

Users generally view multivitamins as a “nutritional insurance policy”, ensuring their bodies and minds continue functioning optimally regardless of any nutrient gaps in the diet.

The theory seems logical too. Provide human biology with a dense source of nutrients, and it’ll take what it needs to smoothly continue everyday operations.

You may wonder why many of the most knowledgeable health professionals oppose the multivitamin trend.

The Many Dangers & Downsides of Multivitamin Supplements

Of all supplement types, multivitamins are the most confusing.

You’ll hear many experts list them as non-negotiables for optimal health. Then some registered dietitians say outdated clichés. Such as “You can get all the vitamins and minerals you need from food”.

You probably CAN'T get all the nutrients you need from whole foods Share on X

Humans require higher nutrient levels than ever before. But as you’re about to see, multivitamin supplements don’t match what you get from diet.

In some cases, the products you’ll get in drugstores or even grocers don’t work like vitamins and minerals naturally do in the body.

That’s if you get the real thing. The supplement industry has a massive issue with labels not matching the actual contents within the capsules. To compound this, multivitamins are usually the worst offenders.

Let’s explore some of the biggest risks of multivitamin supplements. Then, I’ll leave you with some better alternatives to consider.


Multis widely vary in price. You can find bottles for as little as $5, and as much as $200.

Yes, a $5 supplement bottle won’t break the bank. Tragically, those bargain-basement options will cause far more hassle than benefit.

They’ll contain the wrong (and potentially toxic) dosing, dangerous inactive ingredient additives, unhealthy ingredient forms, perhaps cause interactions with medications, or may even cause certain nutrient deficiencies.

Cheap products will likely pass through you, undigested and unutilized by your body.

Plus, many other problems that will soon become apparent.

If you insist on using a multi-supplement, you’ll want to splurge. The only ones I’d consider using would cost over $1 per serving. More on that at the end.

Countless interactions

Are you using any medications or drugs? Supplements can magnify side effects and symptoms, change their potency, or even block their effect.

Each drug has a list of known contraindications.

The more ingredients in a product, the higher your likelihood of experiencing dangerous interactions.

With individual supplement ingredients (i.e. vitamin C, creatine, essential amino acids, or ashwagandha), you can easily verify potential interactions.

Some multivitamins, on the other hand, contain 90+ ingredients. Vitamin K is notorious for interfering with blood thinning medications like warfarin.

But it’s not just pharmaceutical drug interactions.

Some common ingredients in multis like black pepper extract (BioPerine) alter your liver’s ability to process many chemicals. Whether that’s your household cleaning products, things you inhale from air pollution, or even your otherwise-beneficial supplements.

This increases your risk of serious or, in rare cases, even fatal side effects [R].

Random dosing

If you own a multi, go grab the bottle. Flip it over to the “Nutrition Facts” on the back label and scan through the list.

In all but a few products I’ve analyzed, the formulas use crazy dosages. You’ll see many ingredients dosed thousands of percent above your recommended daily intake.

Under the care of a medical professional, certain circumstances and situations warrant huge doses. Mega-dosing of certain nutrients can be harmful.

One of the most important factors depends on the vitamin’s solubility:

  • Water-soluble (mostly harmless): Your body excretes excess amounts through your urine
  • Fat-soluble (exercise caution): Your body cannot easily remove these, so excess amounts accumulate in your liver and tissues

Fat-soluble vitamins include vitamins A, D, E, and K. You can develop toxicity from each, particularly vitamin A. Those that eat healthy nutrient-dense foods are at even higher risk of overdose.

Consuming 3,500% of your vitamin B12 (water-soluble) RDA won’t cause toxicity like 3,500% of your vitamin A RDA would. I’ve seen some products with those numbers too.

Yet manufacturers know that consumers compare products by dosages, so many put far too much in their products.

High-quality brands invest heavily in R&D to make sure they get the nutrient dosages of each right.

Genetics & bioindividuality

One of the primary issues with multivitamins is the very nature of the product. They attempt to fill the position as a universal essential supplement.

Though when it comes to vitamins and minerals several factors play major roles:

  • Genetics
  • Epigenetics/lifestyle
  • Current circumstances
  • Bioindividuality

No two people have the same mineral needs and current mineral levels. I may get tons of vitamin A in my diet and little vitamin K. You might be the opposite.

The multivitamin formula that gets me healthy may make you quite sick Share on X

Too much of just one single ingredient out of the entire formula (sometimes 90+ ingredients) can cause net toxicity instead of benefit.

Then there’s the individual differences. Ranging from your constitutional makeup, to your current lifestyle habits.

Men, for example, accumulate iron to toxic levels more often than women. Smokers need more of certain nutrients and less of others. Pregnant women have different needs still, and even a small imbalance can cause major issues for their offspring.

No universal best nutrient dosage exists. The more ingredients within a product, the greater your potential problems.

Toxic forms

The Most Overrated Supplement of All (Better Alternatives to Multivitamins)

Supplement manufacturers want you to believe that a vitamin/mineral is a vitamin/mineral.

The reality, however, is that these nutrients come in different forms. Each with extremely different effects on the body and brain.

For example, you might see “magnesium” on the back label and recognize this as a powerful supplement. Usually, that’s true. Magnesium is one of the top universally beneficial supplements. That is if you buy the right kind.

Manufacturers might use a cheap form called “magnesium stearate” as an additive to cut manufacturing costs. Although it’s called magnesium, you get none of the benefits and only some potential side effects. Other forms of magnesium, like ionic, glycinate, citrate, and malate do provide the benefits.

Then there’s the issue of “activated” vitamins. Your body must manually process certain nutrients before use. Depending on your genetics, some people cannot handle the typical (cheap) forms which actually take them further out of balance.

Several examples include:

  • Vitamin B12 (Methylcobalamin)
  • Folate (Methylfolate)
  • Vitamin B6 (Pyridoxal 5′-phosphate)

I’ve listed the activated form of each in parentheses.

For this reason, I don’t recommend Athletic Greens and instead prefer these top AG1 alternatives.

Causes deficiencies

I know this sounds paradoxical. How can a multivitamin actually cause nutrient deficiencies?

Two ways. First, they sometimes don’t provide nutrients in the required ratios. This impairs absorption and utilization.

Next and most significantly, through a process called competitive inhibition.

Certain substances compete for absorption. Consuming high doses of one nutrient blocks the absorption of another, causing a deficiency.

Some common examples include:

  1. Magnesium and calcium
  2. Zinc and copper
  3. Iron and zinc [R]
  4. Vitamin A and vitamin D [R]
  5. Vitamin C and iron [R]
  6. Calcium and magnesium
  7. Vitamin C and citamin E
  8. Copper and iron
  9. Folate and vitamin B12
  10. Calcium and zinc
  11. Vitamin D and calcium

Some of these compete at any dosage, and some only at high dosages.

Although the label itself may show 100% of your daily value of both calcium and magnesium, for example, you’ll only absorb calcium and very little magnesium. Driving further imbalances.


Located on supplement labels underneath the nutrition facts, the inactive ingredients list represents everything else in the product aside from what you’re intentionally buying.

Manufacturers virtually always add these inactive ingredients to their products.

Sometimes, to fill the rest of the capsule when the active ingredient only takes up a small part of the space. Sometimes to make the bottling process easier and more efficient. Sometimes to increase shelf life. Among many other reasons.

Adding extra inactive ingredients rarely serves the customer. It simply brings down manufacturing costs.

Here you’ll find all the excipients, binders, flow regulators, artificial ingredients, flavorings, dyes, fillers, and other additives.

Although they’re listed as “inactive” ingredients, they can certainly still affect your body. In some cases, causing reactions or other toxicities. Not only that, but they can also affect your absorption of the primary nutrients.

This problem plagues most supplements, but especially multivitamins.


Chlorella & spirulina tablets turning to powder from degradation
If your bottle of multis doesn’t pass third-party safety testing, you’re wasting money and risking your health

Many doctors and health professionals refuse to use supplements, despite myriad potential benefits.


Lack of regulatory oversight makes the industry a hotspot for fraud and shocking deception. Third-party watchdog groups like the popular frequently test the most popular products on the market.

Depending on the category, as many as half the tested supplements flunk standard quality tests. Sometimes, these products contain lower dosages than mentioned; sometimes, even zero of the ingredients that you’re paying for!

Then there’s the issue of contamination. From heavy metals, to mold mycotoxins, to pathogenic bacteria. Although supplements should all pass these basic safety tests, often they don’t.

Low-quality products are rarely third-party lab tested for quality and safety. So you run an increased risk of contamination and potential harm.

Not only do contaminated multis cause more harm than benefit, but they too can inhibit your ability to absorb key nutrients.

False security

Multivitamins can cause a strong mindset shift away from clean eating.

While I’m all for utilizing the placebo effect, multivitamins cannot substitute for whole foods.

Users may mistakenly believe they’re getting enough nutrients from their multi, and excuse themselves from choosing nutrient-dense foods.

Creating a false sense of security. One that easily compounds the impact of bad choices over the long term.


Manufacturers must balance product shelf life with digestibility.

Supplements often sit on shelves for months—even years—before you purchase.

To minimize cost and waste, they add all kinds of things to the product to stabilize the formula and make it last.

Things like waxy coatings, shellac, or even some types of plastics.

Cheap multis are especially notorious for this.

Users often report undigested multis passing in their stools. Of course, if you’re excreting the intact product, your body cannot assimilate the nutrients either.

No benefits (or worse)

Proponents of multis highlight the seemingly logical theory that they must improve human health.

The majority of research doesn’t support this.

Contrary to what you’d expect, large-scale epidemiological studies regularly show that multivitamins do not confer a reduced risk of death.

In fact, the opposite may be true.

For example, The Iowa Women’s Health study sought to answer this. They surveyed 38,000+ middle-aged women and concluded that regular multivitamin users have a slightly increased risk of mortality than non-users [R].

Perhaps they help not death itself, but the potentially fatal conditions?

A John Hopkins study of 450,000 people concluded that multis do not reduce the risk of heart disease, cognitive decline, cancer, or premature death [R]. They also found that certain synthetic nutrients (common in multis) have harmful effects.

Too much supplemental calcium can actually increase the risk of heart attack and disease [R].

Another long-term randomized clinical trial of 5,947 multivitamin-using male physicians found no change in brain function [R].

In 2024, several recent studies hint at a potential longevity benefit of multis. Yet upon further investigation, you’ll notice that supplement companies funded these studies.

It seems clear that most multis won’t help you live longer, and probably won’t reduce your risk of developing degenerative conditions.

Dynamic formulas

Supplement brands often change their formulas.

The top ones reformulate to improve their products as new research emerges. They proudly announce the changed formula in emails and on the product page itself.

Many, however, take the opposite route. Here’s their playbook.

Shady brands launch with a high-quality product. Through word-of-mouth marketing and paid efforts, they gain market share. After they’ve become known, they silently begin tweaking their formulas.

These untrustworthy vendors swap out premium ingredients (like activated vitamins) with cheap alternatives. They continue business as usual and deliberately remove any evidence (i.e. old product photos) that savvy customers could use to determine that they silently changed their formula.

Although thanks to their new formula, their manufacturing cost and product quality continue to drop, these deceptive brands continue charging the same (sometimes, even more).

The worst part is, if you’re not constantly scrutinizing labels, you may not notice that they changed the formula you bought years (or even decades) ago.

Multivitamin brands are the worst with this tactic.

Better & Safer Alternatives to Multivitamins

Trace minerals and Nick's recommended multivitamin
There are many better alternatives to multivitamins.

If you’ve made it this far, you know I’m not a fan of multivitamins.

They just have too many drawbacks to deserve a spot in nearly 1/3 of American cupboards and in hundreds of millions of homes worldwide.

Multis have time and place, and warrant level caution to pharmaceutical drugs.

So how do you fill potential nutritional gaps in your diet without relying on multivitamin supplements?

Try the following abbreviated version of my Outliyr Bioharmony B.O.O.S.T framework. This is a practical scientific tutorial to maximize results and minimize potential complications.

Start by centering your diet around minimally processed nutrient-dense foods like berries, nuts, and clean animal products.

You’ll probably still have gaps, so you’ll want to add in sources of minerals.

According to researchers like Dr. James DiNicolantonio, 1/3 of Americans have 10 or more mineral deficiencies. Food has much lower levels of minerals than it did a few decades ago, so getting enough from food is virtually unheard of.

I recommend using one of these safe and effective multi-mineral supplements.

Once you have enough minerals, your body has the necessary building blocks to best absorb and utilize vitamins.

Before adding a vitamin product, you’ll probably want to run a high-quality over-the-counter health testing service to identify any specific deficiencies.

If you have a deficiency to fill, instead of a shotgun multivitamin, you can choose products that only contain particular nutrient(s). After a while, you can retest to ensure that your levels have come into a healthy range.

Following a proper nutrient optimization protocol like this helps you save money and get better results, without the common complications of ineffective (and sometimes dangerous) multivitamins.

Ditch Multivitamins & Enjoy Optimal Nutrient Levels

Contrary to popular belief, scientists, savvy biohackers, and many of the top doctors recommend against multivitamin supplements.

From toxic additives and unhealthy forms of ingredients to dangerous contaminants, nutrient “competitive inhibition”, to actually causing their own deficiencies… multis aren’t what they seem.

That’s why much of the research shows that these products have either zero benefit, or in some cases, even cause harm compared to non-users.

I recommend two superior options instead.

Spirulina & chlorella micro-algae supplements are nature’s closest thing to a plant-based multi. For those that prefer animal-based nutrition, organ meat supplements provide vitamins, minerals, and beneficial bioactive peptides.

For those who insist on using a multivitamin, I would only consider the following select products

  • NutriGenesis Multi for Men
  • NutriGenesis Multi for Women
  • Thorne Basic Nutrients

I prefer the NutriGenesis line because the nutrients within it aren’t synthetic like most products, rather closely mirroring the efficacy, bioavailability, and safety of what you find in food.

Thorne products are also great, especially because they’re sometimes used in clinical research. But I like them for those that require methylated vitamins.

Instead of indiscriminately popping multis and feeling that you’ve covered your nutritional requirements, use the optimal approach.

Eat and drink according to nutrient density. Re-mineralize your body with some of the top natural sources. Perform proper bodily testing, and consider using the ingredients specific to your needs.

If you enjoyed this post, please send it to a friend or share it on social media. You’ll be helping raise awareness of the rarely discussed drawbacks of one of the most widely used categories of supplements.

Now, what about you? Do you use multivitamins? Let me know why or why not in the comments below!


Post Tags: Biohacking, Controversial, Dangerous, Nutrition, Supplements, Vitamins & Minerals

Leave a Comment