Cod liver oil is a popular dietary supplement derived from the liver of cod fish. Like most fish oils, it contains the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and also vitamin A and even vitamin D.
Studies suggest that Cod liver oil can reduce blood triglycerides, relieve inflammation, and even ease symptoms of conditions such as rheumatoid arthritis. According to the United States Department of Agriculture’s Dietary Guidelines for Americans 2015–2020, you should eat at least 8 ounces of seafood per week because of these benefits.
Although Cod liver oil is safe for most adults, taking too high a dose may have serious effects on your body.
Here are some side effects of taking excessive Cod liver oil supplements:
- High Blood Sugar: Some studies suggest that taking supplements with high amounts of omega-3 fatty acids could increase blood sugar levels in people with diabetes.
- Bleeding: Excessive fish oil consumption can lead to bleeding gums and nosebleeds.
- Low Blood Pressure: Taking too much Omega-3 fatty acids can lower blood pressure and it may interfere with certain medications and cause problems for those with low blood pressure.
- Diarrhea: Taking high doses of Cod liver oil can lead to diarrhea and it is one of the most common adverse effects of fish oil, alongside other digestive symptoms such as flatulence.
- Acid Reflux: Although Cod liver oil is extremely beneficial to the heart, many people report feeling heartburn after starting to take fish oil supplements. Taking too much fish oil supplements may lead to acid reflux symptoms such as belching, nausea, indigestion and heartburn in some people.
- Stroke: Some animal studies suggest that a high intake of omega-3 fatty acids could decrease the blood’s ability to clot and increase the risk of hemorrhagic stroke.
- Vitamin A Toxicity: Certain types of omega-3 fatty acid supplements, such as cod liver oil, are high in vitamin A, which can be toxic in large amounts.
- Insomnia: Taking moderate doses of fish oil could enhance sleep quality. However, excessive consumption of fish oil can lead to insomnia.
How much Cod liver oil should be taken?
According to a report by Healthline, most health organizations recommend an intake of at least 250–500 milligrams of combined EPA and DHA, or two servings of fatty fish per week. According to the European Food Safety Authority, omega-3 fatty acid supplements can be safely consumed at doses up to 5,000 mg daily. Consult a doctor before taking any supplement.