Side Effects of Cod Liver Oil Capsules

Fish oil supplements such as cod liver oil capsules contain concentrated doses of omega-3 fatty acids. These healthy fats provide anti-inflammatory and cholesterol-lowering benefits that can help reduce the risk of heart disease, stroke, arthritis and other chronic diseases. According to the University of Maryland Medical Center, omega-3 fatty acids are also important for brain function and memory. However, you may experience some mild side effects of cod liver oil capsules and other omega-3 supplements.

Ask your doctor if cod liver oil capsules are right for you. (Image: Stockbyte/Stockbyte/Getty Images)

Fishy Aftertaste

Cod liver oil capsules solve the problem of fishy-tasting and odorous liquid fish oil supplements. However, the capsule breaks down in the stomach, quickly releasing the concentrated cod liver oil inside. The Linus Pauling Institute notes that one of the most common complaints about fish is the fishy aftertaste. This may occur because the cod liver causes belching or stomach acids to rise, leading to heartburn and a pungent taste at the back of the throat. To reduce the risk of this type of heartburn, take your cod liver oil capsule with food and avoid lying down immediately after taking it.

Digestive Disturbances

In addition to belching and heartburn, other digestive side effects from cod liver oil capsules include nausea, gas, bloating and stomachache. The Linus Pauling Institute notes that high doses can also cause loose stools or diarrhea. Taking a time-release cod liver oil or fish oil capsule can help reduce these gastrointestinal side effects. They will most likely decrease on their own as your body adjusts to the fish oil supplement.

Bruising and Bleeding

Cod liver oil and other fish oils help prevent heart disease and stroke, partly because they thin the blood by slowing blood clotting. However, the Linus Pauling Institute warns that in some cases, lowering blood clotting time can increase the risk of bruising and bleeding. If you have a bleeding disorder or if you are taking prescription or over-the-counter medications such as warfarin or acetylsalicylic acid, consult your doctor before taking cod liver oil capsules or any omega-3 fatty acid supplement.

Raised Blood Sugar Levels

Cod liver oil capsules are often recommended for diabetics because they help to reduce the risk of heart and blood vessel disease. However, research published in the "Journal of Diabetes and Metabolic Disorders" in February 2013 noted that this healthy oil supplement did not lower blood sugar levels in male albino rats. In fact, taking cod liver oil capsules raised blood sugar levels. The University of Maryland Medical Center notes that this may occur because the body converts omega-3 fatty acids into sugars. If you have any type of diabetes, use fish oil supplements only under the supervision of your doctor.