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What are the Most Common Cod Liver Oil Side Effects?

B. Miller
B. Miller

Cod liver oil is a dietary supplement that contains high levels of the omega-3 fatty acids, which are EPA and DHA, as well as vitamins A and D. It is most often taken in capsule form and has been shown to lower blood pressure and fats in the blood, known as triglycerides. Other purported benefits include helping with depression, arthritis, kidney disease, heart disease, lupus, and glaucoma. As when taking any dietary supplement, it is important for individuals to consider any potential side effects, and to be aware of any problems.

Fortunately, negative cod liver oil side effects are fairly uncommon. The most common include belching, bad breath, or a bad taste in the mouth. It may also cause heartburn or diarrhea if too much is consumed. One way that people may help prevent these side effects is to always take cod liver oil with meals and never on an empty stomach. Some brands may work better and cause fewer of these side effects for different people, so individuals may want to try a different brand if the side effects persist.

Belching is a common side effect of cod liver oil.
Belching is a common side effect of cod liver oil.

Because this dietary supplement can thin the blood, nosebleeds are another one of the more common side effects. For this reason, it is also important for patients to stop taking cod liver oil before surgery and to notify a healthcare professional of any other supplements being used. Many vitamin and herbal supplements can thin the blood and cause excessive bleeding during surgery. Cod liver oil should generally not be taken with anticoagulant medications either.

Bad breath is a side effect of cod liver oil.
Bad breath is a side effect of cod liver oil.

Cod liver oil lowers blood pressure, so individuals should be careful while taking it if they are also taking blood pressure medicine. The combination of the two can cause the blood pressure to drop too low, which can be harmful. There is also some concern that levels of vitamin A and D could potentially become too high if taking cod liver oil with other multivitamins and vitamin supplements.

Fish oil supplements, including those made from cod liver, are rich in healthy fats, such as omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, commonly called DHA.
Fish oil supplements, including those made from cod liver, are rich in healthy fats, such as omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, commonly called DHA.

Pregnant and breastfeeding women should not take this supplement to prevent any dangerous cod liver oil side effects, as there has not been enough research done to rule out any problems. There is also a potential for any fish oil supplements to contain mercury. Whenever taking any dietary supplement, people should be sure to take it only as directed and to read any warnings on the bottle for possible interactions.

Discussion Comments

Logicfest

It might not be a bad idea to check with a doctor before taking these. There is a danger when it comes to such homeopathic, "natural" supplements -- they are unregulated and various manufacturers suggest different doses. Getting the opinion of a doctor could be beneficial when it comes to any of this stuff.

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    • Belching is a common side effect of cod liver oil.
      By: Dan Race
      Belching is a common side effect of cod liver oil.
    • Bad breath is a side effect of cod liver oil.
      By: Gina Sanders
      Bad breath is a side effect of cod liver oil.
    • Fish oil supplements, including those made from cod liver, are rich in healthy fats, such as omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, commonly called DHA.
      By: Stephen VanHorn
      Fish oil supplements, including those made from cod liver, are rich in healthy fats, such as omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, commonly called DHA.
    • Diarrhea is one possible side effect of taking cod liver oil.
      By: JPagetRFphotos
      Diarrhea is one possible side effect of taking cod liver oil.
    • Side effects of cod liver oil may include heartburn.
      By: kmiragaya
      Side effects of cod liver oil may include heartburn.