Cod Liver Oil – Do’s and Don’ts


Cod Liver Oil

If you have been taking Fish Cod Liver Oil as the supplement for Omega-3 fatty acids, you need to be aware of the right dosage because it can do more harm than good.

What is Cod Liver Oil?

Grandmoms have been force feeding this stinky supplement for a very long time. Cod liver oil (CLO) is exactly what the name suggests, oil extracted from the liver of cod fish. It is considered as one of the best sources of Omega-3 fatty acids and also a source of Vitamins A and D. If you would like to know the benefits of Olive Oil, for health, hair and skin, read here.

Health Benefits of Cod Liver Oil


Cod liver oil has been used for ages in America and Europe as a dietary supplement because of its health benefits –

  • EPA (eicosapentaenoic acid) – is an Omega-3 fatty acid that is good for vascular health and has positive effects on the heart.
  • DHA (docosahexaenoic acid) – another fatty acid that is beneficial for brain, eye and infant development.
  • Vitamin A – Important for good eyesight and healthy skin.
  • Vitamin D – Good for bone and immunity. Read about other immunity building Superfoods, here.
  • Beneficial for those suffering from rheumatoid arthritis, reducing pain and inflammation
  • Also helpful in improving brain function and memory, according to the University of Maryland Medical Center

CLO is available in various forms from capsules to concentrated oil and fermented to organic. Read more about other Superfoods for amazing hair and skin, here.

Potential Risk

If you read the above benefits, CLO looks like harmless nutritional supplements with a funny aftertaste. But there is a downside.

Fish oil is generally recognized as safe in doses less than 3 grams daily, but cod liver oil is different from other sources of fish oil because it’s quite high in vitamin A, which can build to toxic levels.


Our body cannot generate Omega-3 fatty acids on its own, yet they are necessary for heart health.  So it is essential to either obtain it from your diet or  from a daily supplement of 500 mg, according to the Harvard School of Public Health.

A daily dose less than 3 g is generally considered safe, but some cod liver oils contain higher levels of vitamin A, which can be toxic.

According to New York University, individuals suffering from heart diseases or with high triglycerides are administered higher daily doses of 3 to 9 grams.

We would recommend that you buy only the least processed varieties available (like fermented), which can sometimes be a little expensive and difficult to find.  Usually, high-quality CLO is light yellow in color and has a slightly fishy smell and taste.

But be sure to consult a doctor before taking higher doses of these supplements as they can pose some serious side effects.

Vitamin A Toxicity


Cod liver oil contains preformed Vitamin A also known as retinol. Retinol is obtained mostly from animal sources.

  1. Some recent researchers have discovered that it is important to have these two vitamins in the right ratio to get health benefits. The ideal ratio between vitamin A to vitamin D is approximately 10:1 or less.
  2. Processed cod liver oil has altered amounts of synthetic Vitamin A and D that are harmful to our bodies. Some commercially available cod liver oils have the ratio of 100:1, which can be toxic.
  3. These varieties are considered toxic when consumed in large doses because they accumulate in your body over time. Furthermore, retinol bypasses your body’s control mechanisms and increases the risk of toxicity.
  4. Vitamin A toxicity can cause side effects like nausea, headache, fatigue, dizziness, and joint pain. In extreme cases, it can result in liver damage.
  5. Be sure to check the ratio of vitamin A and D, next time you buy cod liver oil, and buy the least unprocessed variety, without exceeding the allowed daily intake.

According to the Weston Price Foundation the recommended dosages for fermented CLO for children up to the age of 12 years is 4650 IU vitamin A and 975 IU vitamin D. And for others the recommended dose is 9500 IU vitamin A and 1950 IU vitamin D.

Warnings and Side Effects of Cod Liver Oil

  • Do not take cod liver oil if you are pregnant or breastfeeding due to a lack of study in this area.
  • Individuals with diabetes should first consult their doctor as ingredients in cod liver oil can cause a rise in blood sugar levels.
  • Individuals with high blood pressure should avoid cod liver oil as it might cause blood pressure to drop dangerously low if used in conjunction with high blood pressure medications.


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