Published: December 22, 2023
Toxic Ingredients To Avoid In Vitamins And Supplements

We may earn a commission, from companies mentioned in this article, at no additional cost to you.


With the rise of “wellness” and people taking a more holistic approach to their health, the vitamin and supplement industry has grown exponentially in recent years; it is a bloated, $36 billion behemoth. As with most industries of that size, it’s rife with fraud, pseudoscience, and marketing scams.

However, with this growth has come many disturbing reports of harmful ingredients in vitamins and supplements. From heavy metals like lead and arsenic to synthetic chemicals, it can be difficult to know which bad ingredients in vitamins and supplements you need to steer clear of to safeguard your health.

In this article, we will discuss sixteen harmful ingredients to avoid in vitamins and supplements. Arm yourself with knowledge to make informed choices and ensure the wellness boost you seek is free from potential risks.

Say goodbye to questionable additives and embrace a healthier, informed approach to supplementing your nutrition.

Key Takeaways

  • Identify and steer clear of harmful ingredients in vitamins and supplements to prioritize your well-being.
  • Learn about bad ingredients in vitamins and supplements that can have adverse effects on your health.
  • Understand which vitamins and supplements can be toxic when certain ingredients are present.
  • Make informed choices by being aware of the harmful ingredients commonly found in vitamins and supplements.

16 Toxic Ingredients To Avoid In Vitamins And Supplements


1. GMOs

Genetically Modified Organisms, or GMOs, are plants or animals that have been created through the process of gene splicing. This is a process where genes from different species are combined to create a new organism. GMOs have been a source of much controversy in recent years. They are dangerous and unhealthy.

Not only are GMOs present in the food industry, but also in the wellness industry. One of the most common GMO products is vitamin C. Vitamin C is often derived from corn, and a large percentage of corn in the United States is genetically modified.

It is important to be aware of GMOs. These are harmful ingredients in vitamins and supplements as many products on the market today contain them. So, it is important to know what you are putting into your body. Look for the Non-GMO Project Verified seal to be sure that the product you are considering is not made with GMOs.

This research showed:

“The biggest threat caused by GM (genetically modified) foods is that they can have harmful effects on the human body.

It is believed that consumption of these genetically engineered foods can cause the development of diseases which are immune to antibiotics.”

2. Pesticides

Studies show that pesticides can be harmful to your health, with some studies even linking pesticide residue in vegetables to Parkinson’s disease. Some vitamins and supplements are loaded with them.

The environmental impact of pesticides is well documented, but many people don’t realize that these chemicals are also harmful to your health. These days, traces of pesticides have been found in everything from produce to water.

You may be surprised by just how many bad ingredients in vitamins and supplements are out there without you even knowing or realizing. Choosing a brand without toxic pesticides is a good way to protect your body from any harm that might come along with taking nutritional supplements.

This study concluded:

“Pesticides affect a number of enzymes and physiological systems i.e. reproduction, nervous, immune, endocrine, blood coagulation, hematology, cardiovascular, respiration, metabolisms, and fluid, and electrolyte balance.

They have carcinogenic and mutagenic potential also. It affects several organs of human beings, but the liver is most susceptible.

The increased formation of reactive oxygen and nitrogen species, resulting in increased lipid peroxidation in several tissues, mainly brain, skeletal muscle, RBC, etc., and depletion of antioxidant status, were reported in several studies of various pesticide exposed population.”


3. Lead

Lead is a naturally occurring mineral that is essential for human health. It is found in small amounts in soil and water. Plants absorb lead from the soil, and animals eat plants that contain lead. Humans can also consume lead by eating meat, fish, and poultry that have been exposed to lead.

Lead is a dangerous toxin that can cause serious health problems. Even low levels of lead exposure can damage the brain and nervous system, and cause learning and behavioral problems. Children are especially vulnerable to lead poisoning, which can permanently affect their development.

According to these findings from the EWG:

“Several of the multivitamin products tested contained high levels of lead, including one women’s multivitamin that contained 15.3 micrograms of lead per daily dose–more than 10 times the amount of lead allowed without a warning label in the state of California.”


4. Arsenic

Used in rat poison and pesticides, arsenic is sometimes found in trace amounts in water. However, that doesn’t mean you should pop an arsenic supplement. Consuming any level of arsenic can lead to nausea, vomiting, stomach pain, diarrhea, and blurred vision.

Even more serious effects include damage to your kidneys and nervous system, skin lesions, or cancer.

There are naturally occurring forms of arsenic that exist in some foods like rice or carrots—but they don’t pose a significant health risk when consumed normally because they are quickly eliminated by your body. Supplements might not be so lucky.

It’s best to just stick with food sources for vitamin A since supplements can contain as much as 250 times more than you need per day. Remember: More isn’t always better!

Here is what this study showed:

“Arsenic is associated with anemia, gastrointestinal effects, poor appetite, weight loss, and neurotoxicity. It also can affect a developing fetus and cause adverse pregnancy outcomes.”


5. Cadmium

This heavy metal is a known carcinogen and can also negatively impact bone formation. It’s found in a wide range of supplements, including multivitamins, calcium supplements, and vitamin D. Supplements with zinc, selenium, iron, or magnesium often contain added cadmium.

So, which vitamins can be toxic? To stay safe, choose these supplements only from reputable brands and steer clear of anything containing zinc or selenium.

One study even found that eight out of ten multi-vitamins contain excess amounts of heavy metals! That’s insane! How are we supposed to trust our health to any product containing toxic substances like these?

Another study found:

“30% of analyzed samples had levels of Cd above allowable levels. Cadmium excessive intake affects mostly the kidney and to a lower extent the reproductive system.”

6. Mercury

You’ll also want to avoid any vitamins that contain mercury or organic thimerosal, a preservative. Mercury can cause adverse reactions in people who are sensitive to it, and while organic forms of thimerosal are less toxic than their mercury-containing counterparts, they can still lead to nervous system damage if consumed over time.

Since some supplement companies may not list all ingredients on their labels, you may not be aware you’re taking it. If a supplement says no mercury added on its label but does not have an independently verified purity report for trace elements, don’t take it.

Research showed:

“Mercury (Hg) is a fairly common environmental pollutant. Chronic exposure to this element may cause, inter alia, kidney damage, and disturbances in the functioning of the nervous system.

Our research has shown that the highest average Hg content was found in DS used for lowering glucose levels (23.97 ± 38.56 μg/kg).”

7. PCBs (Polychlorinated Biphenyls)

The majority of fish oil supplements contain Polychlorinated biphenyls (PCBs), which studies have linked to birth defects, impaired immune system development, and reproductive problems.

Unfortunately, PCBs aren’t just in fish oil supplements; they can also be found in most other multivitamins and various over-the-counter medications.

Luckily, eating non-oily fish is a good way to get your omega 3 fatty acids without harmful chemicals. Also note that in light of mounting evidence that even low levels of PCBs are harmful, some companies are no longer using them in their products.

If you don’t see non-PCB on your label, assume it contains these harmful chemicals.

This study demonstrated:

“Environmental and occupational exposures to PCBs have been associated with liver, kidney, endocrine, and neurodevelopmental adverse effects.”

Titanium Dioxide

8. Titanium Dioxide (TiO2)

A whitening agent is used in some vitamins, cosmetics, and toothpaste. It’s often included in children’s vitamins to give them a white color, but it can be an allergen and is potentially toxic when inhaled or swallowed.

The most commonly known problem with TiOis that it causes severe skin reactions with long-term exposure; frequent hand-washing after contact should prevent these issues from arising.

But long-term ingestion of TiOhas also been linked to pulmonary disease and a weakened immune system and TiOis a carcinogen, it’s best avoided just in case.

Here are the results of the research conducted:

“Animal experiments have shown that chronic exposure to E171 can lead to translocation and bioaccumulation of TiOvia the bloodstream, in various organs, including the liver, kidney, placenta, and brain.

Across different types of models, gene expression patterns have been reported that are associated with inflammation and tumor development.

In-vivo, ex-vivo, and in-vitro experiments, mainly conducted with TiOnanoparticles, show that TiOcan result in the formation of ROS, which is associated with the induction of genetic damage, the initiation, and stimulation of inflammation, and the promotion of tumor formation.”

9. Magnesium Silicate

Magnesium silicate is also known as talc. It is used as a filler, and an anti-caking agent, and is similar in composition to asbestos. In supplement form, magnesium silicate may cause nausea, vomiting, diarrhea, lung problems, and rarely even death. In addition to being very harmful in high doses, magnesium silicate is difficult for your body to absorb.

Some mineral supplements use tricalcium phosphate or calcium carbonate as binding agents instead. To avoid any unpleasant side effects and make sure your body can fully utilize what you’re putting into it, choose a supplement that doesn’t contain magnesium silicate.

Sodium Benzoate

10. Sodium Benzoate

Why is sodium benzoate in vitamins and supplements? It’s used as a preservative and it also can release formaldehyde, which you know is toxic to humans and animals. That can harm your immune system, damage your DNA, and cause cancer.

You shouldn’t consume any more than 0.1 mg of sodium benzoate per kg of body weight (approximately 9 grams for an average adult). The upper limit, by US standards, is 1 mg per kg of body weight (or 90 grams for an average adult) because it causes adverse effects in some people when consumed in excess.

Even if you don’t react to it now, your health could be affected later down the road. So why would anyone put something these harmful ingredients in vitamins or supplements? Well, they wouldn’t—unless they had no choice. And there are only two reasons why: FDA regulations and money.

There are no legal limits on how much sodium benzoate can be added to products sold in America. So manufacturers use it without worrying about how much they use—and without telling you about it on product labels!

Manufacturers do so because it’s cheap and effective at killing bacteria, yeast, and mold that grow inside bottles of vitamins or supplements after their expiration date passes.

This study reported:

“It is notable that several reports from animal and cell culture models have suggested that sodium benzoate and hippurate might have a significant impact on glucose homeostasis.

For example, intravenous infusion of benzoic acid in sheep resulted in a rise of serum glucose, insulin, and glucagon without concurrent glucose administration, suggesting a combined secretagogic action on insulin and glucagon, as well as a potential influence on insulin sensitivity.”

Hydrogenated Oils

11. Hydrogenated oils

To improve stability, manufacturers add hydrogen to unsaturated vegetable oils. This process creates trans fats and reduces essential fatty acids in your body that protect against health conditions like diabetes and cancer.

Avoid vitamin E supplements that contain these oils. These are the bad ingredients in vitamins. Instead, opt for vitamin E in foods like almonds, spinach, and sunflower seeds.

The health benefits of antioxidants are much more powerful when you get them through diet than taking them as supplements because they are produced by your body’s natural processes.

Think of it this way: Your body makes vitamin C and you can also take a supplement to increase your vitamin C levels (because it’s not synthesized fast enough). How do you think your body will react to those additional synthetic nutrients? It doesn’t need all that extra!

You’re better off getting your vitamins from food where they belong – in their natural form. You should know that some vitamins can be harmful if taken in large doses or if you have certain medical conditions. You should always consult with a doctor before starting any new regimen or changing your current one.

Research proved:

“Direct connection of trans fatty acids with cardiovascular diseases, breast cancer, shortening of pregnancy period, risks of preeclampsia, disorders of nervous system and vision in infants, colon cancer, diabetes, obesity, and allergy.”


12. Lactose

Some vitamins and supplements contain lactose, which is found in many common supplements. Not only does lactose taste bad and cause gas and bloating, but it can also be a major trigger for those with intolerances or allergies.

If you experience digestive distress after taking supplements regularly, contact your doctor as soon as possible to determine whether you are one of these people.

Most people think that taking a supplement is healthy, but when you take into account what’s actually in these pills and powders, it’s alarming to realize how harmful they can be.

Plus, most vitamin products have extra fillers like lactose added to make them taste better or feel more palatable, but they’re not doing your body any favors.


13. Sulfites (Sulphites)

Sulfites, the harmful ingredients in vitamins and supplements, are common preservatives that prevent food from spoiling. But they can cause respiratory reactions and allergic symptoms, including nausea, asthma, and hives.

Sulfites may be banned by 2020 under new FDA guidelines, but many doctors say they already should have been banned a long time ago because they’ve proven to be too dangerous for most people. Anyone who gets an acute reaction needs to stay away from sulfites.

If you have asthma or allergies — conditions that make you more likely to have problems with sulfites — talk to your doctor about using them cautiously at home or not at all.

This study concluded:

“Sulphites are widely used as a preservative and antioxidant additive in the food and pharmaceutical industries.

Exposure to sulphites has been reported to induce a range of adverse clinical effects in sensitive individuals, ranging from dermatitis, urticaria, flushing, hypotension, abdominal pain, and diarrhea to life-threatening anaphylactic and asthmatic reactions.”


14. Carrageenan

Often found in so-called whole food vitamin supplements, carrageenan is a type of seaweed extract. Despite its increasing popularity, carrageenan has been linked to several side effects and ailments, including intestinal issues and even cancer.

Some studies have also found that carrageenan may increase inflammation in our bodies. In most cases, it’s best to avoid any supplement with carrageenan as an ingredient. Instead, try eating whole foods that naturally contain these essential nutrients instead of taking pills or powders full of chemicals.

According to the Cornucopia Institute:

“Carrageenan exposure clearly causes inflammation; the amount of carrageenan in food products is sufficient to cause inflammation, and degraded carrageenan and food-grade carrageenan are both harmful,” says Dr. Joanne Tobacman, MD, Associate Professor of Clinical Medicine, University of Illinois at Chicago.”

Artificial colors, flavors, and dyes

15. Artificial flavors, colors, and dyes

Do you think artificial flavors, colors, and dyes are bad for you? The answer is a resounding Yes, as these harmful ingredients in vitamins and supplements can cause several different health problems.

You’ve heard that artificial dyes are used in your favorite ice cream, candy, and other junk foods but did you know they’re also found in some of your vitamins?

Artificial dyes like Yellow 5, Red 40, and Blue 1 have been shown to cause severe allergic reactions in children and adults alike.

Many studies show that children who consume a lot of food with artificial colors have more behavioral problems than those who don’t. In recent years, some countries have banned these harmful chemicals outright because they’re known to cause cancer, hyperactivity, organ damage, and more.

This research demonstrated:

“Artificial dyes derived from petroleum are found in thousands of foods. In particular breakfast cereals, candy, snacks, beverages, vitamins, and other products aimed at children are colored with dyes.

In 2008 the Center for Science in the Public Interest (CSPI) in Washington, DC, petitioned the Food and Drug Administration (FDA) to ban artificial food dyes because of their connection to behavioral problems in children.

Two years later a new CSPI report, Food Dyes: A Rainbow of Risks, further concludes that the nine artificial dyes approved in the United States likely are carcinogenic, cause hypersensitivity reactions and behavioral problems, or are inadequately tested.”


16. Added sugar

Sugar is basically a problem all on its own. The average American takes in 22 teaspoons of added sugar a day, according to data from Mintel. Added sugar often contains harmful ingredients like high fructose corn syrup, which can lead to cardiovascular problems, diabetes, and other health issues.

The biggest problem with bad ingredients in vitamins and supplements is that they often contain too much sugar, making them incredibly harmful for diabetics and those struggling to lose weight.

For example, prenatal vitamins often contain up to 31 percent of their weight in sucrose (table sugar), while other brands pack pesticides into a supplement containing extracts of orange and peach pits.

If you must take a vitamin or supplement that contains sugar, look for no added sugar on its label. To be safe, you should avoid taking supplements that contain insane amounts of sugar. Instead, try adding more fresh organic fruits and vegetables into your diet!

This study showed:

“Not only do added sugars displace nutritionally superior foods in the diet, but they may also deplete nutrients from other foods that have been consumed, as well as from body stores, in order to enable their proper oxidation and liberate their calories as energy.

Additionally, the consumption of added sugars damages the mitochondria and hence impairs energy generation. Moreover, overconsuming added sugars may result in a kind of ‘internal starvation’ (via leptin and insulin resistance) leading to further hunger signals in the body.

Added sugars promote nutrient and energy deficit and through this novel pathway promote obesity.”

Frequently Asked Questions About Toxic Ingredients To Avoid In Vitamins And Supplements

What are the toxic ingredients to avoid in vitamins and supplements?

Bad ingredients in vitamins, such as magnesium stearate and artificial colors, sweeteners, should be avoided. Check for these harmful ingredients on labels.

How can I identify bad ingredients in vitamins and supplements?

Scrutinize labels for bad ingredients in vitamins, including magnesium silicate and artificial sweeteners. Opt for formulations without these additives and preservatives.

Which vitamins can be toxic due to specific ingredients?

Be cautious of which vitamins can be toxic, especially those with excessive iron or synthetic forms. Check for harmful ingredients in vitamins and choose wisely.

What steps can I take to make informed choices about supplements?
Stay informed about harmful ingredients in vitamins and supplements by researching labels. Prioritize your health by avoiding bad ingredients in vitamins.

What are the toxic ingredients to avoid in vitamins and supplements?

Watch out for harmful ingredients in vitamins, including artificial colors and high fructose corn syrup. Stay vigilant for a healthier supplementation routine.

Related Articles:


As more and more people are taking vitamins and supplements, it is important to be aware of the bad ingredients in vitamins and supplements.

This article listed 16 of the most toxic ingredients to avoid in vitamins and supplements. If you are taking any vitamins or supplements, be sure to check the ingredients list to make sure that these harmful ingredients are not included.

Let me know in the comments below any other toxic ingredients to avoid in vitamins and supplements.


1. Bawa, A S, and K R Anilakumar. “Genetically Modified Foods: Safety, Risks and Public Concerns-A Review.” Journal of Food Science and Technology, Springer India, Dec. 2013, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3791249.

2. Patil, Jyotsna A, et al. “Effect of Vitamin E Supplementation on Biochemical Parameters in Pesticides Sprayers of Grape Gardens of Western Maharashtra (India).” Indian Journal of Clinical Biochemistry : IJCB, Springer-Verlag, Apr. 2012, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3358367.

3. “Tests Reveal High Lead Levels in Multivitamins.” Environmental Working Group, 12 May 2022, https://www.ewg.org/news-insights/news/tests-reveal-high-lead-levels-multivitamins.

4. Hauptman, Marissa, and Alan D Woolf. “Childhood Ingestions of Environmental Toxins: What Are the Risks?” Pediatric Annals, U.S. National Library of Medicine, 1 Dec. 2017, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982419.

5. Korfali, Samira Ibrahim, et al. “Evaluation of Heavy Metals Content in Dietary Supplements in Lebanon.” Chemistry Central Journal, BioMed Central, 18 Jan. 2013, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3560192.

6. Puścion-Jakubik, Anna, et al. “Mercury Content in Dietary Supplements from Poland Containing Ingredients of Plant Origin: A Safety Assessment.” Frontiers in Pharmacology, Frontiers Media S.A., 3 Nov. 2021, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8595131.

7. Faroon, Obaid, and Patricia Ruiz. “Polychlorinated Biphenyls: New Evidence from the Last Decade.” Toxicology and Industrial Health, U.S. National Library of Medicine, Nov. 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4673019.

8. Bischoff, Nicolaj S, et al. “Possible Adverse Effects of Food Additive E171 (Titanium Dioxide) Related to Particle Specific Human Toxicity, Including the Immune System.” International Journal of Molecular Sciences, MDPI, 28 Dec. 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7795714.

9. Lennerz, Belinda S, et al. “Effects of Sodium Benzoate, a Widely Used Food Preservative, on Glucose Homeostasis and Metabolic Profiles in Humans.” Molecular Genetics and Metabolism, U.S. National Library of Medicine, Jan. 2015, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4289147.

10. Dhaka, Vandana, et al. “Trans Fats-Sources, Health Risks and Alternative Approach – A Review.” Journal of Food Science and Technology, Springer-Verlag, Oct. 2011, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3551118.

11. Vally, Hassan, and Neil LA Misso. “Adverse Reactions to the Sulphite Additives.” Gastroenterology and Hepatology from Bed to Bench, Research Institute for Gastroenterology and Liver Diseases, 2012, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4017440.

12. “Carrageenan: Risks and Reality.” Cornucopia Institute, 31 Aug. 2021, https://www.cornucopia.org/2013/12/carrageenan-risks-reality.

13. Potera, Carol. “The Artificial Food Dye Blues.” Environmental Health Perspectives, National Institute of Environmental Health Sciences, Oct. 2010, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2957945.

14. DiNicolantonio, James J, and Amy Berger. “Added Sugars Drive Nutrient and Energy Deficit in Obesity: A New Paradigm.” Open Heart, BMJ Publishing Group, 2 Aug. 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4975866.

Sharing is caring!


Keep Reading

FREE Clean Eating

Grocery List

We respect your privacy. Unsubscribe anytime.

Skip to content