Cod liver oil is a fatty oil substance that is abstracted from the liver of Atlantic cod. It is often used as a nutritional supplement because it is a rich source of essential fatty acids and vitamins A and D. The exact level of nutrients found in cod liver oil is determined by the breed of the cod, (Gadus).
The first therapeutic use of cod liver oil dates back to 17th century England. While it continued to be used as a remedy from that point forward, it became more well-known in the early 20th century when it was used to manage vitamin D deficiency. While it was not exactly tasty, children of the 1930s were given cod liver oil in order to help prevent vitamin D deficiency. Since then it has become a daily supplement for many Europeans and Americans.
The body cannot manufacture essential fatty acids and must get them from food. Cod liver oil is an excellent source because it contains omega-3 fatty acids as well as vitamins A and D. Omega-3s are healthy fats that are vital for the health of every cell in the body. Two of the most important omega-3s are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). DHA is found in large quantities in the eyes and the brains of mammals as it helps to make neurotransmitters. DHA is essential for the growth and functional development of the brain in infants, as well as the maintenance of normal brain function in adults. If you have blood issues or take medication, always check with your physician before taking cod liver oil as it could potentially thin the blood.
Vitamin A is essential for normal vision, a healthy immune system, reproduction, and growth and development. Vitamin D is important for the body’s absorption of calcium, which is critical for healthy bones and teeth. The body normally manufactures vitamin D when exposed to sun rays, but lifestyle and environmental changes have resulted in a serious vitamin D deficiency worldwide. Cod liver oil is one of the most dense sources of both vitamins A and D. A possible alternative to getting your D from cod liver oil is Care/of’s Vitamin D3 The Sunshine Vitamin and Calcium Plus Bone Hugs and Harmony.
Vitamin D is essential for bone health and cod liver oil is among the richest food sources of vitamin D with approximately 450 IU per teaspoon. Maintaining adequate levels of vitamin D helps to support bone mineral density. According to this study, cod liver oil has been shown to support bone mineral density in vitamin A-deficient rats.
Vitamin A plays a role in maintaining a clear cornea and helps to produce fluids that keep the eyes moisturized and lubricated. This study reports that vitamin A is found in the highest concentration in the eyes. Proponents of cod liver oil believe that both omega-3 fatty acids and vitamin A can play a protective role in overall eye health. Since they’re both plentiful in cod liver oil, it may potentially offer support for eye health, though more research is needed.
There is research that indicates that consuming fish and other types of seafood as part of a balanced diet promotes heart health, especially when the fish is consumed in place of less healthy foods. Cod liver oil and other omega-3 supplements can help manage triglyceride levels already in normal range among people with low dietary omega-3 intakes. There is also some evidence to support the positive impact cod liver oil may have on healthy lipid levels in adults according to this study. More research is required. Eating a heart-healthy diet, getting regular exercise, and making healthy lifestyle choices are proven benefits for cardiovascular health.
Proponents of cod liver oil contend that it aids in both mood and cognitive performance. This long-term animal study found that long-term administration of cod liver oil supported cognitive health negatively impacted by stress. More research, especially with human subjects, is required.
There are initial animal studies that suggest the mucoprotective and anti-secretory properties of cod liver oil, though more research is needed. Other options for stomach and digestive health include probiotics, prebiotics, digestive enzymes, and fiber like Care/of’s premium chia-flax product The Fiber Starters.
While cod liver oil is generally considered safe when taken as directed, there are people who should exercise caution when taking it. If you are pregnant, it is important to consult your physician before you consume any cod liver oil as it is especially rich in both vitamins A and D. There is an upper limit of vitamin A during pregnancy of 3000 mcg, and for vitamin D the upper limit is 4,000 IU or 100mcg.
There are also common cod liver oil potential side effects such as mild headaches, an upset stomach, a metallic taste in your mouth, and the dreaded bad breath and fishy burps. These side effects typically do not require medical attention unless they last a long time or become problematic.
There are rare instances of more serious side effects such as allergic reactions (hives, skin rash, swelling of the lips, face or tongue, and itching), yellowing of the skin or eyes. If these occur, speak to your physician as soon as possible and discontinue use immediately.
It is always recommended to consult with your physician before you make any changes to your supplement protocol, especially if you are taking any medications. Special precaution should be taken by anyone with blood issues, or anyone taking blood-thinning medication, as cod liver oil can also potentially thin the blood. Any person who supplements vitamins A or D should also check with their physician before taking cod liver oil, especially if pregnant.
While there are concerns about the number of servings of fresh fish a person eats each week because of the potential toxins and pollutants, there is no such concern when it comes to fish oils. They undergo a distillation process which ensures that all toxins and pollutants have been filtered out of the oil.
The typical dosage of cod liver oil recommended may vary by product, but most suggest 1-2 tsp daily for a healthy adult. You may want to start on the lower side in order to get used to the taste and to monitor any potential unpleasant side effects. If you want to increase your dose about the recommended maximum, it is best to consult your physician before doing so.
You also might want to consider mixing your cod liver oil with juice, lemon water, apple sauce, yogurt, almond butter, a smoothie, or anything that might disguise the fishy taste, or make it somewhat less fishy.
When choosing your cod liver oil, look for a reputable brand, ideally one that contains antioxidants that can keep the oil from oxidizing. A reputable brand will not add flavor enhancers to remove the odor or mask the taste of the cod liver oil, though some brands may add an extract such as mint or lemon to make it more palatable. Fermented cod liver oil is also an option. The livers are fermented in order to produce more vitamins, which can make the nutrients more bioavailable.
Helpful hint: Once you have purchased cod liver oil, store it in a cool, dark place, or in the refrigerator to prevent it from spoiling and turning rancid. You’ll be able to tell by the smell if it has turned rancid.
Cod liver oil has been around since the 17th century and is purported to offer many health benefits, as it is an especially rich source of both vitamins A and D, and is a good source of omega-3 fatty acids. As always, if you’re thinking about changing your supplement protocol, consult your physician or registered dietician before doing so.