Cod liver oil

Cod Liver Oil: Properties, What is it for, How to Take it

We find out about all the properties and benefits of cod liver oil and how to properly take it

Cod liver oil is a type of fish oil supplement. Just as it is the case of all these fish oil supplements, cod liver oil has a high content of omega-3 fatty acids which are associated with various beneficial health properties, and with vitamins A and D.

This supplement is often sold in capsules and we can buy it in herbalists and specialty shops. In the following we’re going to tell you about what properties cod liver oil contributes with and how we can add it on our diet.

Cod liver oil benefits

Cod liver oil is an excellent source of nutrients and can contribute with interesting benefits to our health. It’s rich in vitamins, omega-3, iodine and phosphorus.

This supplement is often recommended for the general strengthening and prevention of childhood illnesses. However, it must be consumed in moderation given that a surplus of vitamins A and D may be harmful to your health.

1. High content of vitamins A and D

Most of this product is extracted from Atlantic cod liver. This oil has been used for a long time to soothe pain in the joints and treat rickets, an illness that causes fragile bones in children.

It’s different from regular fish oil, which is extracted from fatty fish tissues such as tuna, herring, anchovies and mackerel.

Liver is rich in fat-soluble properties such as vitamins A and D. With only one teaspoonful of this type of oil it gives us 90% of our daily needs of vitamin A, and 113% of our daily needs of vitamin D. 

Vitamin A has many functions in the body, such as preserving our eye health as well as our brain function and skin health. Vitamin D plays an important part in keeping our bones healthy by regulating our calcium intake.

2. It may keep inflammation down

The omega-3 fatty acids to be found in cod liver oil may keep chronic inflammation down since it suppresses the proteins that provoke it. The vitamins found in cod liver may keep chronic inflammation down since these neutralize harmful free radicals. 

3. It may improve bone health

Cod liver oil is a great dietetic source of vitamin D, which helps the body to absorb calcium, a necessary mineral to have strong bones.

Some research undertaken demonstrates that a supplement of vitamin D, such as cod liver oil, together with a diet rich in calcium, may keep down bone loss among adults and strengthen fragile bones in children. 

4. It may keep joint pain down

Currently, there is no cure for rheumatoid arthritis, but research suggests that cod liver oil may reduce joint pain and improve the symptoms of this illness, such as the rigidity and the swelling of the joints.

In a study undertaken by some researchers, 43 people took a capsule of 1 gr of this type of oil on a daily basis for three months. It was demonstrated that the symptoms of rheumatoid arthritis, such as morning rigidity, were being kept down.

5. It may preserve eye health

It’s been demonstrated that omega-3 fatty acids and vitamin A found in cod liver oil protect us from eye illnesses caused by inflammation.

A number of studies carried out on people who consumed a greater amount of omega-3 fatty acids and enjoyed a diet rich in vitamin A, demonstrated that these keep the risk of suffering from glaucoma down in a considerable way.

Although vitamin A is excellent for eye health, high doses of this aren’t recommended as they may lead to toxicity.

6. It may keep down the risk of a heart illness

Research has demonstrated that those who eat fish on a regular basis have a much smaller risk of suffering from a heart illness. This effect may be attributed to its content of omega-3 fatty acids.

Unfortunately, few studies have delved into the link between cod liver oil and heart illnesses, for many studies lump this product together with normal fish oil.

 Much more specific research is therefore in order to be able to establish a clear link between this type of oil and heart illnesses.

7. It may help to improve the symptoms of anxiety and depression

It’s been demonstrated that there is a link between chronic inflammation, and anxiety and depression. Omega-3 fatty acids found in cod liver oil may diminish the swelling, and, as a result, keep the symptoms of anxiety and depression down.

Research undertaken on 21,835 people demonstrated that taking cod liver oil keeps the symptoms of anxiety and/or depression down. However, although omega-3 fatty acids help to keep these symptoms down, its general effect seems to be small.

8. It may help to heal stomach or intestinal ulcers

Research on animals signals that this supplement may help treat ulcers, not least those that develop in the stomach or in the intestine. Although its use to help to heal ulcers seems promising, more research is necessary on humans to derive relevant recommendations.

How many doses may we take?

This product is very easy to add to our diet. We may find it in different formats, although capsules and liquid are the most popular.

There are no established patterns for the consumption of cod liver oil, which explains the reason why most recommendations are based on safe consumption levels of omega-3 fatty acids, vitamin A and D.

A common dose is two teaspoonfuls, but taking up to one full spoonful a day is broadly speaking safe. Higher doses aren’t recommended, since they would lead to an excessive intake of vitamin A.

Although this product is extremely healthy, some people have to watch out with its intake since it may work as an anticoagulant.

It’s therefore advisable to see a doctor should we be simultaneously taking medicine for blood pressure or for thinning the blood. Besides, pregnant women must also consult a doctor, for high levels of vitamin A may harm the baby. 

Where to acquire cod liver oil?

When it comes to acquiring this supplement, it’s important to take into account a number of factors to be able to enjoy a product fit for our needs and tastes.

One of the most important points is to verify its quality. Not all products that are sold as cod liver oil include this ingredient 100%. We must therefore carefully read the label to make sure we’re acquiring pure oil.

We must pay attention to those products that include less than 60% of this ingredient, since the rest is filled up with vegetal oils of low quality, other type of fish, additives, preservatives and artificial vitamins.

Its flavor is also important, since the capsules of this supplement often come in different flavors or are bland. Moreover, they also include pleasant scents and are highly digestible. These are often covered with gelatin.

Its price is often proportional to the quality of the product.  A high-quality supplement of cod liver oil often costs roughly 0.60€ per 10 mg.


  • Gilaberte, Y., Aguilera, J., Carrascosa, J. M., Figueroa, F. L., de Gabriel, J. R., & Nagore, E. (2011). La vitamina D: evidencias y controversias. Actas dermo-sifiliográficas, 102(8), 572-588.

  • Nasiff-Hadad, A., & Meriño-Ibarra, E. (2003). Ácidos grasos omega-3: pescados de carne azul y concentrados de aceites de pescado. Lo bueno y lo malo. Revista Cubana de Medicina, 42(2), 128-133.

  • Rajakumar, K. (2003). Vitamin D, cod-liver oil, sunlight, and rickets: a historical perspective. Pediatrics, 112(2), e132-5.