Properties and Benefits of Cod Liver Oil

Cod liver oil

Cod liver oil has long been known for its beneficial effects on human health and is currently one of the most popular dietary supplement among people of all ages. As its name suggests, cod liver oil is the oil made from cod fish liver and the two main sources for it are the Atlantic cod (Gadus morhua) and the Pacific cod (Gadus macrocephalus). Though it can be found in dietary supplements, eating fresh cod liver supplies one with the same nutrients found in supplements.

Cod liver oil is a great source of vitamins A, D and E, iodine as well as an excellent source of healthy Omega-3 fatty acids in the form of EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic acid), with the first being essential for brain and eye health and only found in fish sources, algae and seafood, and in nutritionally negligible amounts in purslane. In addition to contributing to bone health and exercising a beneficial action on the skin and immune function, among others, cod liver oil is also known for its protective action on the heart and vascular system.

Cod liver oil benefits

Cod liver oil first began being used around 1824 as an effective treatment against rickets, a childhood disease affecting the poor and malnourished. Rickets was primarily caused by a severe, prolonged vitamin D deficiency resulting from poor nutrition and engendered bone fractures and deformities such as bow legs, knock-knees, skull deformities, pigeon chest, spine deformities and so on. Supplying children’s diet with cod liver oil was found to reverse some of the effects of the disease and prevent debilitating long-term health problems. With the advent of modern medicine, numerous studies on the importance of cod liver oil and its impact on human health have been conducted, all of which have revealed the beneficial action of the oil.

Why is cod liver oil good for you?

Simple: because it contains extraordinary amounts of some essential nutrients and more than generous amounts of others. Find out below some of the most notable nutritional facts of cod liver oil.

1) Vitamin A (RAE 30000 µg, or 100000 international units, IU).
2) Vitamin D (250 µg, in the form of vitamin D2 and D3, or 10000 IU).
3) Vitamin E.
4) Omega 3 fatty acids EPA and DHA.
5) Iodine.

Before listing the health benefits of cod liver oil consumption, I would like to draw attention on the fact that the oil is beneficial for both children and adults who cannot meet their demands of Omega-3 or vitamins A and D in particular. Also, it is important to note that supplementation should be done with great care which is why it might be best to consult a medical professional to better assess your nutritional status and individual requirements.

Cod liver oil

What are the benefits?

What is cod liver oil good for? Here is a list of the most notable 6 health benefits of of the fish oil:
1) Prevents vitamin D deficiency and associated health problems. While it may not seem a serious issue, vitamin D deficiency can have a horrendously negative impact on one’s health. If left untreated, it can lead to signs and symptoms such as frail bones and bone fractures associated with osteoporosis, rickets, skin problems, low energy levels, chronic fatigue, muscle pain, impaired growth in children, even asthma, cognitive problems in adults, impaired cognitive development in young children or an increased risk for certain cancers, autoimmune diseases, to name a few.

If you do not have adequate amounts of vitamin D in your diet, the body will draw it from your bones to your bloodstream (you need it there too), which will not only lead to bone demineralization, but also cardiovascular problems, cognitive decline, depression etc. For some people, exposure to sunlight might not be enough, especially if they have a darker skin because dark skin contains more melanin, a compound which protects the skin from harmful radiation from the sun, but also blocks vitamin D production.

Supplementing with cod liver oil is a great option for both children and adults prone to vitamin D deficiency as a result of a lack of exposure to sunlight (because they are living in areas with little sunlight, work during the day in indoor facilities or because of religious principles encouraging a more covered up attire) poor diet, problems digesting milk products, etc.

2) May benefit arthritis sufferers. According to research, cod liver oil may have a beneficial impact on the quality of life of arthritis sufferers. Basically, taking the oil on a regular basis is reported to have improved joint pain and stiffness associated with arthritis, osteoarthritis and rheumatoid arthritis. However, lifestyle and dietary factors may contribute to a more or less visible improvement of the condition. It has been suggested that the Omega-3 fatty acids from cod liver oil exert a strong anti-inflammatory action contributing to a reduction in pain symptoms.

3) Contributes to heart and vascular health. Cod liver oil is most famous for its positive impact on cardiovascular health. It would appear that the healthy fatty acids in the oil boast antioxidant properties and thus contribute to maintaining healthy blood vessels. Moreover, Omega-3 fatty acids have been shown to help clear plaque buildup from artery walls, thus reducing the risk of them blocking arteries to the point that they may rupture and endanger one’s life. This mechanism is also believed to help reduce atherosclerosis risks.

The fats in cod liver oil are the healthy type, the ones our body needs most. Replacing other foods with fish and derivate oils such as cod liver oil means we increase our intake of healthy fats which, in turn, contributes to higher HDL (good) cholesterol and lower LDL (bad) cholesterol and triglyceride levels, hence the cardiovascular benefits of cod liver oil.

4) Essential for brain health. Our brain works on and is mostly made from fats, particularly healthy, polyunsaturated Omega-3 fatty acids. It has been recently discovered that one type of Omega-3 fatty acids, called DHA, is an essential brain nutrient. DHA is needed for cognitive development in babies, learning, memorizing things, thinking, preventing cognitive decline in older adults and all things brain-related as well as for good vision.

While ALA (alpha-linoleic acid), an Omega-3 fatty acid from plants is partially converted into DHA, the conversion rate is so low (0-8% in ideal conditions) that almost any ALA intake is insignificant, requiring for us to still get all the DHA Omega-3 we need from fish and seafood sources. In other words, including fish and fish oils such as cod liver oil in our diet (depending on individual requirements) is crucial for having a healthy brain.

5) Promotes skin health. Cod liver oil contains excellent amounts of both vitamin A and vitamin  E, two nutrients of great importance for skin health. Both vitamins exert a powerful antioxidant activity and hunt down dangerous free radical molecules that can cause serious damage to cells and accelerate the aging process.

Completely excluding fats from your diet is the worst thing you can do for your skin because it lives off healthy fats that keep it elastic, young-looking, radiant and wrinkle-free, helping it retain moisture, fight off free radicals, not to mention the wound healing properties. Fish and derivate fish oils such as cod liver oil are great ways to improve your skin aspect naturally and prevent premature aging.

6) Great for healthy eyes, good energy levels, beautiful hair, skin and nails and fertility. The almost incredible amounts of vitamin A in cod liver oil are responsible for the beneficial effects of the oil on our eyesight. Vitamin A promotes visual acuity and good vision in dim light. In addition to this, it appears that DHA, a form of Omega-3 from fish sources, is required by our retina for better vision. Iodine, another important nutrient in cod liver oil, boasts a variety of health benefits.

Iodine supports the thyroid gland to produce specific thyroid hormones that regulate heart rate, blood pressure, brain function, cognitive performance as well as body weight and body temperature. It also contributes to healthy skin, strong hair and nails and good fertility in women. Enough iodine in your diet reduces the risk of hypothyroidism.

Potential side effects

Of course, many of us are worried about heavy metal poisoning. Fish is known to contain mercury as well as other heavy metals so there is a risk of side effects and health problems should we eat too much. However, cod liver and other fish oils are especially filtered to make them perfectly safe for consumption. Nevertheless, make sure not to purchase obscure brands as you will have no guarantee they contain what they say they do.

Always choose quality cod liver oil and take it according to instructions or your doctor’s recommendations. Remember to follow recommendations closely because cod liver oil contains rather insane amounts of vitamins A, D, E and you may risk hypervitaminosis, a conditions in which your body stores a lot of vitamins, with potential toxic effects.

A common side effect of cod liver oil is acid reflux. Given that it is an oil, it can cause regurgitation of stomach juices and subsequent heartburn, even in the limited amounts it is supposed to be consumed. Supplementing with the oil on an empty stomach or taking it later in the day or at night, before sleeping, especially if you have gastroesophageal reflux disease, is likely to cause acid reflux and heartburn. If you have asthma, the acid reflux can predispose to an episode too.


Cod liver oil is especially good for children undergoing a growth spurt, children and adults who do not have a good exposure to sunlight, who exhibit mild to severe vitamin D deficiency symptoms, are lactose intolerant or do not generally consume a lot of dairy products. However, remember to put other dietary supplement complexes aside while you are taking cod liver oil in order to avoid hypervitaminosis. You can still take your vitamin C, let’s say, but avoid supplements with vitamins also found in the oil.