Bruce Abrahamse

Bruce Abrahamse

March 25, 2025

8 Surprising Supplements That Could Be Harmful to Your Gut Health

There is a seemingly unlimited variety of different supplements that claim to support your health, enhance lifestyle, and address deficiencies. There are supplements that boost energy levels, support your immune system, improve joint and bone health, and enhance athletic performance. However, while many supplements do provide a range of health benefits, in certain situtations, there are also supplements the may be damaging gut health. Let’s take a look at 8 supplements that could be harming your gut health. 

Magnesium Supplements

pink supplement pills
Credit: Pexels

Magnesium is an essential mineral that plays a part in hundreds of bodily chemical reactions. It promotes better sleep, reduces anxiety, and prevents cramps. In the correct amounts, it can also aid digestion and help relieve constipation. However, in higher doses, it can cause issues with your digestive system, such as cramps, bloating, and diarrhea. Taking too much magnesium can result in a laxative effect as it draws water into the intestines. It is regarded as one of the supplements damaging gut health because it can cause an imbalance in gut flora. 

Calcium Carbonate

white tablets
Credit: Pixabay

Calcium is needed for the maintenance of bone density and helps prevent conditions such as osteoporosis. It is also known to help prevent muscle contractions and reduce acid reflux and heartburn. Calcium is also essential for nerve function and maintaining a healthy pH balance. However, this supplement can also cause gas, bloating, and constipation. This specific type of calcium is less soluble, often leading to intestinal disturbances and discomfort. This makes it more difficult for the digestive tract to find a healthy equilibrium. 

Iron Supplements

orange supplements
Credit: Pixabay

Iron supplements offer a range of health benefits, such as treating anemia, enhancing your immune system , and increasing energy levels. However, taking high doses can irritate your digestive tract, resulting in feelings of nausea, stomach pain, and constipation. Additionally, high doses of iron can alter your digestive system’s flora and promote pathogenic bacteria growth. This can lead to inflammation, boating, and an upset stomach. 

Read More: 8 Heart Healthy Supplements To Consider (and 2 To Avoid)

Prebiotics

veggie capsules
Credit: Pixabay

Prebiotics are known to stimulate good bacteria growth in the gut and improve digestive processes. They also enhance the absorption of nutrients and reduce inflammation. However, if taken in excess amounts or in the wrong form, it can actually cause various issues. Overloading your gut with prebiotics can cause excessive fermentation, which can cause gas and bloating. For individuals who already suffer from gut issues such as IBS, this supplement can actually worsen the condition.  

High-Dose Antioxidants

supplements on a plate
Credit: Pixabay

Antioxidant supplements contain compounds that help combat and neutralize harmful free radicals. They also fight against oxidative stress, help improve heart health, and support your immune system. Antioxidants also support your body’s detoxification process and slow down the signs of aging. Yet, once again, too much of a good thing can be bad for you! Studies have shown that high-dose vitamin E and beta-carotene supplements can upset the delicate gut bacteria equilibrium. Beta-carotene in high doses also seems to increase the risk of developing lung cancer in smokers. 

Fish Oil Supplements

fish oil supplements
Credit: Pixabay

Fish oil supplements contain beneficial omega-3 fatty acids. These supplements also lower blood pressure, reduce chronic inflammation, and even enhance brain function. Fish oil supplements also improve infant development and enhance immune system function. However, if taken in low-quality forms, it can actually have a negative impact on your gut. If taken in excess, it can also lead to GI issues, including indigestion, bloating, nausea, and diarrhea. Some people also find it difficult the high fat content in fish oil supplements, resulting in the above-mentioned symptoms. 

Multivitamins with Too Much Zinc

white tablets
Credit: pixabay

Zinc is considered an essential mineral that plays an important role in various bodily functions. Zinc helps activate immune cells, helps with the growth and repair of tissue, and has anti-inflammatory properties that reduce skin conditions. Yet, if taken in high doses, zinc irritates the lining of your stomach, resulting in digestive issues. Taking multivitamins with too much zinc can cause a gut bacteria imbalance. This can potentially damage beneficial microbes in your gut. The best way to avoid taking too much zinc is to make sure that your multivitamin contains the recommended doses of zinc. 

Certain Weight Loss Supplements

woman measuring her waist.
Credit: Pixabay

The most obvious benefit of these supplements is that they help you lose weight. Yet, many supplements are unregulated and need to be treated with caution. Many of these weight loss supplements contain harsh ingredients that can damage your gut health in multiple ways. They can potentially change gut function, impacting the body’s ability to absorb nutrients, leading to gut irritation and inflammation. The lack of proper regulation in the weight loss supplement industry often means that they contain dangerous contaminants and harmful additives. It’s best to discuss which supplements you plan on taking with your doctor and sticking to trusted brands.

Read More: 3 Supplements You Should Think Twice Before Purchasing, According to a Pharmacist