From better vision to better mood, you'll find that the benefits of cod liver oil are extensive and promising. While it's been used as a remedy for generations, researchers are now just diving into what makes cod liver oil so good for you - and why you should pay a little more attention to this old-fashioned supplement.
Jump to What is it? | Nutrition | Benefits | Why Take It? | How Much to Take | Risks | What to Look For | Recommendations | Common Questions
What is cod liver oil?
Cod liver oil is a fatty substance extracted from the livers of codfish, and people use it as a dietary supplement because it is rich in essential fatty acids and key nutrients such as vitamins A and D.
Northern Europeans, particularly in Scandinavia and the Hebrides, have used cod livers as food and cod liver oil for its health benefits for generations. It was thought to fortify the body against cold, dark winters(1). Given that winters at extreme northern latitudes tend to be long with little sunlight, cod liver oil would offer an excellent source of vitamin D when consistent exposure to sunlight itself wasn't possible.
The earliest recorded use of cod liver oil as a therapeutic supplement dates to 17th century England when writers described its use in fighting rheumatoid arthritis as well as joint pain and inflammation (2). The use of cod liver oil as a remedy continued throughout the 19th century into the early 20th century when it was used to treat consumption (a lung disease) and rickets, a disease caused by vitamin D deficiency (3). By the 1930s, it became a common daily supplement for many European and North American children.
Nutrition
Cod liver oil is a good source of three specific nutrients: omega-3 fatty acids, vitamin A and vitamin D (4). It's these healthy fats and fat-soluble vitamins that are likely responsible for so many of cod liver oil's benefits. While you can get these nutrients from a variety of other foods, such as cold-water fish and organ meats, cod liver oil is the single densest source of these key nutrients.
A teaspoon of cod liver oil contains about 40 calories, 4500 IU vitamin A, and 450 IU vitamin D as well as 888 mg omega-3 fatty acids. This represents about 90% of the daily value for vitamin A and 113% of the daily value for vitamin D.
- Docosahexaenoic acid (DHA) is an omega-3 fatty acid and an essential nutrient, especially for the brain (5), vision, and nervous system (6). DHA's protective role on neurological health and brain development makes it a particularly important fat for babies and young children whose brains and bodies are growing quickly.
- Eicosapentaenoic acid (EPA) is an omega-3 fatty acid that acts as a partner to DHA, and you'll often see them referenced together. Eicosapentaenoic acid supports the heart (7) and is a key nutrient for combatting inflammation and supporting mood (8).
- Vitamin A is a fat-soluble vitamin that performs several important functions for your body. Among its most important roles are supporting your vision and immune system function as well as cellular and reproductive health (9). It is also a powerful antioxidant.
- Vitamin D is also a fat-soluble vitamin, and it plays a critical role in bone health, and deficiency in the vitamin is linked not only to bone diseases such as rickets, but also to depression (10, 11) as well as poor heart and metabolic health, autoimmune disease, and even cancer (12).
Benefits of Cod Liver Oil
You can attribute most of the benefits of cod liver oil to its omega-3 fatty acids and high vitamin A and D content. We know that, individually, these nutrients help support the heart, bones, and eyes as well as cognitive, reproductive, and immune system health. And it's fair to extrapolate some of these benefits to foods that are rich sources of these key nutrients, especially when they're used in the context of an otherwise nutrient-dense diet.
Inflammation
Chronic inflammation and oxidative stress are at the root of many diseases and health problems. The key nutrients in cod liver oil are highly anti-inflammatory. Low levels of vitamin D are associated with many inflammatory diseases (13). Increasing vitamin D intake through food, supplements, or sunlight exposure may help achieve optimal benefits (14).
In addition to vitamin D, vitamin A is also a powerful antioxidant that fights inflammation. And cod liver oil is an excellent source of it, containing roughly 4500 IU or about 90% of the daily value in a single teaspoon. The vitamin A in cod liver oil is retinol (or true, preformed vitamin A).
The anti-inflammatory benefits of cod liver oil, specifically, have been studied, too. One study took a look at the inflammatory marker c-reactive protein in athlete's blood. The researchers found that people who took cod liver oil regularly had lower levels of inflammation (15).
Bone Health
Vitamin D is a nutrient that is critical for healthy bones. Cod liver oil is the single richest food source of this nutrient, containing about 450 IU of vitamin D per teaspoon.
Maintaining good vitamin D levels helps to support bone mineral density, and taking cod liver oil is appears to be a good way to just that (16, 17). This is especially true for people who live far away from the equator, and who do not have enough access to sunlight to produce adequate vitamin D year-round (18).
Cognitive Health
One of the key nutritional benefits of cod liver oil is that it is rich in docosahexaenoic acid (DHA), an omega-3 fatty acid that plays a large role in human health - especially cognitive health. It plays a critical role in cognitive health throughout your lifetime, including in infancy and childhood as well as old age (19). A high intake of DHA along with other key nutrients, such as vitamin D, may help support brain function and cognitive ability (20).
This is especially important for pregnant women and breastfeeding mothers. Maternal intake of DHA during pregnancy and while breastfeeding conveys benefits to their babies (21). A study in Norway found that the babies of women who had higher intakes of DHA during pregnancy exhibited better problem-solving skills, which is associated with higher IQ (22).
Cardiovascular Health
Together, vitamins A and D as well as omega-3 fatty acids appear to support heart health. Cod liver oil is a rich source of all three nutrients. While research on the way cod liver oil benefits the heart directly is limited, examining the role of these nutrients can help give us a picture of how they work together.
Vitamin A is a powerful antioxidant and it helps calm inflammation, and some researchers have examined the nutrient's role in inhibiting the development of heart disease (23). Vitamin A can help neutralize free radicals that contribute to poor heart health (24).
People who regularly eat fish tend to have better cardiovascular health than those who don't, and researchers attribute this benefit to fish's high omega-3 fatty acid content (25, 26). Cod liver oil is a concentrated source of these healthy fats.
Mood
The nutrients found in cod liver oil benefit mood, too. Omega-3 fatty acids, as well as vitamin D, play a role in mood. People with lower levels of EPA and DHA, omega-3 fatty acids found in cod liver oil, tend to experience higher rates of severe anxiety and depression (27). And omega-3 fatty acids have a neuroprotective effect which may explain why they appear to ease anxiety and depression in some people (28). Adolescents with lower levels of vitamin D tend to experience depression and disturbed mood at higher rates than those with adequate levels, and vitamin D supplementation appears to offer some alleviation (29).
Vision
The vitamin A and omega-3 fatty acids in cod liver oil appear to benefit vision and eye health, too. This is especially true for glaucoma and age-related macular degeneration.
Glaucoma is the second leading cause of blindness in the world, and research suggests that both omega-3 fatty acids and vitamin A can play a protective role in eye health. Given that cod liver oil combines both nutrients in a single supplement, researchers are hopeful that it may offer vision support for those who need it most (30). Similarly, people with higher intakes of omega-3 fatty acids tend to have a lower risk of macular degeneration (31).
Why Take It?
While the benefits of cod liver oil are fairly clear, more research into its specific effects and its use as a supplement is always needed. It's important to note that it's a concentrated source of these key vitamins, and many of the diseases mentioned above are associated with a low intake of these key nutrients.
Currently, vitamin D deficiency is rampant in the U.S. with 70% (32) of US children and 42% of adults (33) having insufficient or deficient levels of the vitamin. Further, 95% of children and 68% had lower than optimal levels of omega-3 fatty acids. For 88% of adults, that put them in the high-risk category for heart disease (34).
Given the strikingly inadequate levels of both vitamin D and omega-3 fatty acids coupled with their relative benefits to health and well-being, finding a way to increase their intake is important. Cod liver is a rich source of both nutrients, and easy to take.
It's important to note that you can get omega-3 fatty acids from plant sources, but marine sources, such as cod liver oil and cold-water fish, are optimal. For example, flax seeds are rich source of alpha-lipoic acid (ALA), but the human body has a difficult time making the conversion from ALA to the more valuable EPA and DHA which is why eating fish (or taking a marine oil supplement like cod liver oil) is important (35, 36).
What's the alternative?
If you can't take cod liver oil, you can get many of its benefits by eating foods rich in omega-3s, vitamin A, and vitamin D. Spending an appropriate amount of time in the sunlight to optimize vitamin D levels is also helpful, too.
For EPA and DHA, eat plenty of sustainable seafood such as wild-caught salmon, rockfish, anchovies, and sardines. Caviar and fish roe are also excellent sources, too. Some people who avoid fish will take an algal oil supplement instead.
For vitamin A, eat organ meat such as liver in pâté or take desiccated liver supplements. These are sources of retinol or true vitamin a, the same kind that gives cod liver oil its benefits.
You can also eat plenty of vividly colored fruits and vegetables, such as leafy greens, carrots, mangos, and papaya. These contain beta carotene, which, in the right circumstances, your body can convert to true vitamin A.
For vitamin D, try eating plenty of oily fish such as salmon, mackerel, herring, and halibut, as well as oysters. Liver is also a fairly good source of the vitamin, too.
How much cod liver oil should you take?
The typical dose for cod liver oil is 1 teaspoon daily for adults and a few drops up to ¼ teaspoon daily for children. For my family, I take 1 teaspoon cod liver oil daily during the winter months when I have less access to the sunlight, and less during the summer.
Remember to talk with your health care provider before starting any new supplements, including cod liver oil, and do not take more than the manufacturer's recommended dose without talking with your doctor first.
Risks and Side Effects
Many women who are pregnant or breastfeeding take cod liver oil because of its high DHA and vitamin D content, since these nutrients support their growing baby. Some research suggests it supports metabolic health and blood sugar regulation during pregnancy while also fighting inflammation (37).
However, other experts warn that the high vitamin A content of the supplement may pose a risk to the developing baby. As always, check with your doctor or midwife to determine what's right for you, your baby, and your pregnancy.
Additionally, cod liver oil is rich in omega-3 fatty acids. As a result, it may interact with certain medications, especially blood thinners (38). You should always talk to your doctor before beginning new supplements, especially if you take medication.
What to look for when buying a cod liver oil
Cod liver oil is typically produced from the livers of Atlantic cod, which has been historically plagued with sustainability issues such as overfishing, although stocks are improving especially in well-managed fisheries (39). Buy oil from producers who practice sustainable fishing techniques, such as catching by hook-and-line, or who are certified sustainable by the Marine Stewardship Council.
In addition, cod liver oil is fragile thanks to its omega-3 fatty acid content. In essence, without proper care it'll go rancid quickly and you'll lose all of the cod liver oil's benefits. So look for oil that is carefully handled from production, through bottling, to storage. It should have a pale, straw color and a fresh, slightly fishy flavor.
Recommended brands
Look for brands that produce clean, fresh-tasting oil and use sustainable methods from well-managed fisheries. In addition, a good-quality brand of cod liver oil will typically have certificates of analysis and make those available to the public upon request.
Rosita Extra Virgin Cod Liver Oil is premium cod liver oil with impeccable sourcing. It's sustainably produced from Arctic cod caught one fish at a time by hook-and-line. They post the results of their testing publicly on their website, too.
Dropi Cod Liver Oil also produces excellent oil from sustainably managed Icelandic fisheries. They also offer the ability to trace each bottle on their website for increased transparency.
Nordic Naturals Arctic Cod Liver Oil makes cod liver oil that is available both in liquid form and in capsules. It's sustainably sourced in Norway and easy to find in most well-stocked health food stores as well as online.
Common Questions
While both fish oil supplements and cod liver oil are good sources of omega-3 fatty acids including docosahexaenoic acid and eicosapentaenoic acid, only cod liver oil contains vitamins A and D. These vitamins are absent in regular fish oil.
You can find cod liver oil in any well-stocked natural foods store; however, oil quality varies from brand to brand. So you may wish to buy higher quality oils from brands practicing ethical and sustainable fishing techniques, and these brands are easily available online directly from their manufacturers or from stores specializing in natural foods and supplements.
No.
Store unopened bottles in a cool, dark cupboard and pay attention to the use-by date on the bottle. Keep opened bottles in the fridge for up to 3 months, taking care to seal the bottle tightly each time you open it.
Cod liver oil capsules are resistant to oxidation and can be stored at room temperature, away from light and heat until the expiration date on the bottle.
Cod liver oil should taste pleasant and clean, similar to fresh sushi. If it has an acrid or rancid aroma or flavor, discard it.
You can take cod liver oil by spoon or in capsule form. In the early 20th century, when cod liver oil was commonly given to small children, mothers would often serve it with orange juice to off-set the oil's flavor.
References
- Griffing, George T. “Mother was right about cod liver oil.” Medscape journal of medicine vol. 10,1 8. 11 Jan. 2008
- Kumaravel Rajakumar; "Vitamin D, Cod-Liver Oil, Sunlight, and Rickets: A Historical Perspective." Pediatrics August 2003
- Raynor, John. Cod Liver Oil: Its Uses, Mode of Administration, Etc.
- Rushton, Clark and Company. (1849)
- Nutritiondata.org. Fish oil, cod liver: nutrition facts and calories. (2022)
- Sun, Grace Y et al. “Docosahexaenoic acid (DHA): An essential nutrient and a nutraceutical for brain health and diseases.” Prostaglandins, leukotrienes, and essential fatty acids vol. 136 (2018)
- Calder, Philip C. “Docosahexaenoic Acid.” Annals of nutrition & metabolism vol. 69 Suppl 1 (2016): 7-21. Mason, R Preston et al. “Emerging Mechanisms of Cardiovascular Protection for the Omega-3 Fatty Acid Eicosapentaenoic Acid.” Arteriosclerosis, thrombosis, and vascular biology vol. 40,5 (2020): 1135-1147.
- Firth, Joseph et al. “The efficacy and safety of nutrient supplements in the treatment of mental disorders: a meta-review of meta-analyses of randomized controlled trials.” World psychiatry : official journal of the World Psychiatric Association (WPA) vol. 18,3 (2019): 308-324.
- Mayo Clinic. Vitamin A. 2022.
- Föcker, Manuel et al. “Effect of vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients - a randomized controlled trial: study protocol.” BMC psychiatry vol. 18,1 57. 1 Mar. 2018
- Aghajafari, Fariba et al. “Vitamin D Deficiency and Antenatal and Postpartum Depression: A Systematic Review.” Nutrients vol. 10,4 478. 12 Apr. 2018
- Kim, Dohee. “The Role of Vitamin D in Thyroid Diseases.” International journal of molecular sciences vol. 18,9 1949. 12 Sep. 2017
- Yin, Kai, and Devendra K Agrawal. “Vitamin D and inflammatory diseases.” Journal of inflammation research vol. 7 69-87. 29 May. 2014
- Charoenngam, Nipith, and Michael F Holick. “Immunologic Effects of Vitamin D on Human Health and Disease.” Nutrients vol. 12,7 2097. 15 Jul. 2020
- Hansen, Mette Wærstad et al. “Regular consumption of cod liver oil is associated with reduced basal and exercise-induced C-reactive protein levels; a prospective observational trial : A NEEDED (The North Sea Race Endurance Exercise Study) 2014 sub-study.” Journal of the International Society of Sports Nutrition vol. 18,1 51. 28 Jun. 2021,
- Mavroeidi, Alexandra et al. “Seasonal variation in 25(OH)D at Aberdeen (57°N) and bone health indicators--could holidays in the sun and cod liver oil supplements alleviate deficiency?.” PloS one vol. 8,1 (2013)
- Eysteinsdottir, Tinna et al. “Cod liver oil consumption at different periods of life and bone mineral density in old age.” The British journal of nutrition vol. 114,2 (2015)
- Wacker, Matthias, and Michael F Holick. “Sunlight and Vitamin D: A global perspective for health.” Dermato-endocrinology vol. 5,1 (2013)
- Weiser, Michael J et al. “Docosahexaenoic Acid and Cognition throughout the Lifespan.” Nutrients vol. 8,2 99. 17 Feb. 2016
- Martínez García, Rosa María et al. “Estrategias nutricionales que mejoran la función cognitiva” [Nutrition strategies that improve cognitive function]. Nutricion hospitalaria vol. 35,Spec No6 16-19. 7 Sep. 2018
- Rees, Alison et al. “Prenatal maternal docosahexaenoic acid intake and infant information processing at 4.5mo and 9mo: A longitudinal study.” PloS one vol. 14,2 e0210984. 13 Feb. 2019
- Braarud, Hanne Cecilie et al. “Maternal DHA Status during Pregnancy Has a Positive Impact on Infant Problem Solving: A Norwegian Prospective Observation Study.” Nutrients vol. 10,5 529. 24 Apr. 20
- Palace, V P et al. “Antioxidant potentials of vitamin A and carotenoids and their relevance to heart disease.” Free radical biology & medicine vol. 26,5-6 (1999)
- Zhang, P-Y et al. “Cardiovascular diseases: oxidative damage and antioxidant protection.” European review for medical and pharmacological sciences vol. 18,20 (2014)
- Raatz, Susan K et al. “Issues of fish consumption for cardiovascular disease risk reduction.” Nutrients vol. 5,4 1081-97. 28 Mar. 2013,
- Hu FB, Bronner L, Willett WC, et al. "Fish and Omega-3 Fatty Acid Intake and Risk of Coronary Heart Disease in Women." JAMA. 2002
- Larrieu, Thomas, and Sophie Layé. “Food for Mood: Relevance of Nutritional Omega-3 Fatty Acids for Depression and Anxiety.” Frontiers in physiology vol. 9 1047. 6 Aug. 2018
- Liu, Joanne J et al. “Omega-3 polyunsaturated fatty acid (PUFA) status in major depressive disorder with comorbid anxiety disorders.” The Journal of clinical psychiatry vol. 74,7 (2013)
- Campisi, Susan C et al. “Assessing the Evidence of Micronutrients on Depression among Children and Adolescents: An Evidence Gap Map.” Advances in nutrition (Bethesda, Md.) vol. 11,4 (2020)
- Huang, Wen-Bin et al. “Cod liver oil: a potential protective supplement for human glaucoma.” International journal of ophthalmology vol. 4,6 (2011)
- Merle, Bénédicte et al. “Dietary omega-3 fatty acids and the risk for age-related maculopathy: the Alienor Study.” Investigative ophthalmology & visual science vol. 52,8 6004-11. 29 Jul. 2011
- Kumar, Juhi et al. “Prevalence and associations of 25-hydroxyvitamin D deficiency in US children: NHANES 2001-2004.” Pediatrics vol. 124,3 (2009)
- Forrest, Kimberly Y Z, and Wendy L Stuhldreher. “Prevalence and correlates of vitamin D deficiency in US adults.” Nutrition research (New York, N.Y.) vol. 31,1 (2011)
- Murphy, Rachel A et al. “Long-chain omega-3 fatty acid serum concentrations across life stages in the USA: an analysis of NHANES 2011-2012.” BMJ open vol. 11,5 e043301. 10 May. 2021
- Gerster, H. “Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?.” International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition vol. 68,3 (1998)
- Burdge, Graham C, and Philip C Calder. “Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults.” Reproduction, nutrition, development vol. 45,5 (2005)
- Yang, Shuli et al. “Cod-Liver Oil Improves Metabolic Indices and hs-CRP Levels in Gestational Diabetes Mellitus Patients: A Double-Blind Randomized Controlled Trial.” Journal of diabetes research vol. 2019 7074042. 28 Dec. 2019
- 5 Things to Know about Omega-3s for Heart Disease. National Center for Complementary and Integrative Medicine. (2022)
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Melissa says
Hi Jenny! When I started reading your email, I immediately thought, "oh no, here's another health person recommending vitamin D to the general public." I was so relieved when I clicked on your blog and saw that you were actually recommending cod liver oil. I am a recently graduated master's student who did her capstone project on vitamin D. You may be interested to know that the latest research is pointing more in the direction that low vitamin D levels are actually due to inflammation and epigenetic changes in vitamin D converting enzymes. Thus, the precursors are not being converted to vitamin D. So, it's not low vitamin D levels that are impairing peoples immune systems, but immune activation/inflammation is lowering people's vitamin D levels. I love your recommendation of cod liver oil because it's a natural, much healthier form of vitamin D that is dosed in amounts found in nature, and the EPA and DHA work toward reducing inflammation.
When you talk about the statistics of low vitamin D levels it's no surprise, as so much of this country's population eats a Standard American Diet, which is highly inflammatory. It actually all makes sense. In any case, I love your blog, your work toward getting people to eat healthier, and your great advice!
Tara says
Hello Jenny,
What are your thoughts on Nordic Naturals? Also, there is a new product made by Nutra Sea that is called Nutra Veg that has only DHA and EPA omegas.
I am just looking for a more affordable option for our large family.
Kind regards,
Tara
Jenny says
I think Nordic Naturals is a fine choice.
Dal says
Hi. You mentioned taking it in the morning on an empty stomach essentially. Is that the best time to take it? I've read conflicting opinions of taking it in the morning versus taking it with a fatty meal. Therefore, I've been taking it with dinner. Have you done any research on this? I use the same fish oil, and it's pricey, so I'd rather get the most out of it possible. Thank you!
Jenny says
I really don't know, and simply take it when it's convenient to do so.
Jose F. Medeiros says
I wish Vegans would understand this and not experiment with their newborns and young children by forcing them to also be vegans.
Erin says
Hi. I recently bought 2 bottles of the Rosita clo without ever having tasted clo. I figured out this morning that pouring a little into a spoon of balsamic vinegar makes it much more palatable. Would this affect the benefit of taking the oil?
Dailey says
Hi! Love your info on cod liver oil. I had previously bought green pastures but could not stomach it, was much too strong! I want my family to start taking cod liver oil and want to try this brand. My question is how much should I give to my children and how young do you start them on it. I have a 4 yr old, 2 year old, and 5 week old ???? All info is greatly appreciated.
Jenny says
Hi Dailey,
Dr. Price recommended only small amounts (~1/4 tsp) during winter months or times when children wouldn't get adequate sunlight. I wouldn't give any supplementary foods to a 5 week old, as the baby should get what he or she needs from your milk.
Glenn says
This may seem like a silly question...
But doesn't eating bacon entirely defeat the point of taking cod liver oil?
I mean, if you're taking cod liver oil to be healthy, and eating something like bacon, which is VERY unhealthy,
you're sort of throwing your money down the drain by consuming cod liver oil.
Jenny says
It is silly, and, no, bacon is not "unhealthy."
Sophie says
Hi Jenny, do you or know of people who have found noticeable improvement with their teeth and gums since taking EVCLO? I am trying to improve my dental health and was wondering if EVCLO would be especially helpful to do this.
Thank you!
Jenny says
Yes, when I've received it by mail, it has always arrived with a cold pack.
Melissa says
Definitely stop using FCLO from Green Pastures, and don't starf taking it. WAP Vice President came out with a report on the product & it is very disappointing.
sarah says
Do you take it with butter oil?
Joanna says
I tried the Rosita oil earlier in the year because I was worried that I wouldn't get the FCLO down. Bizarrely enough, I just couldn't get along with the taste of the Rosita - I found it really fishy and it took me ages to get the small bottle down. Saying that, I had no issue with the product as it is clearly very pure and superior to most. I have since started using the orange flavour FCLO and have no problem at all with that. In fact, I don't know what the fuss is all about to be honest but then this just shows how everyone is different!
NG says
Hello,
Once opened, does the Rosita EVCLO require refrigeration?
Thanks!
mariam says
where can you buy it from the UK?
Damien says
You can buy EVCLO in the UK here https://www.purenutrience.com/product/extra-virgin-cod-liver-oil-evclo/
Monica Seabourn says
I recently purchased the EVCLO and we are loving it! Much more palatable and pleasing to the nose 🙂 We eat plenty of grass fed butter, but it can be hard to get enough into our two year old. I purchased the Extra Virgin Butter oil to add in for my little, but I'm unsure as to how much I just give him. He's getting in 1/2 tsp to 1 tsp of EVCLO a day. How much EVBO should he get?
Thanks
sarah roe says
Hi Jenny!
What are your thoughts on needing to take this with butter oil? I eat a lot of grass fed butter and whole raw milk. Do you think that's a sufficient complement or no?
Many Thanks,
Sarah Roe
Jenny says
Dr. Price always administered HVBO with cod liver oil; however, I generally just eat plenty of butter and take my cod liver oil daily.
Raine Saunders says
I have every confidence in the Green Pasture Products fermented cod liver oil due to the fact that recent tests from different sources have shown the product to be safe, and that so many folks have successfully taken this product for many years. It is certainly true that some cannot take this product, and I am grateful options exist for those who still want a non-industrially produced cod liver oil for the health benefits it confers.
There are people who cannot eat various foods for various reasons, but that does not make the foods rancid or dangerous. There are those with histamine sensitivities, for instance, who cannot consume fermented foods or broths. Digestive, auto-immune, and genetic issues sometimes cause this to happen, but the foods themselves are not necessarily harmful. It is the same with cod liver oil, as I've heard people share that they cannot consume the fermented cod liver oil due to a sensitivity of one kind or another, or perhaps that they are allergic to cod.
There are other foods we eat every day with no backward glance such as cheese, yogurt, meats, and fermented vegetables, which contain some of the same "questionable" elements as those in fermented cod liver oil - putresine and cadaverene. These are just two elements which have been tested in all of these foods, and were found to be safe for consumption.
See page 48 of this .pdf document:
http://www.efsa.europa.eu/en/efsajournal/doc/2393.pdf
Jenny says
Raine, it's important that, in your recommendation of GP, you disclose that you work with them at their booth at Wise Traditions and that, further, Nourishing Ourselves/Nourishing Our Children receives funding from Green Pastures.
Raine Saunders says
As a clarification: at the time of this posting, I had retired my position with Nourishing Our Children. I was affiliated with Nourishing Ourselves, but NO is a separate project and does not receive funding from GPP. I can't speak for the current status.
I do work for GPP at the Wise Traditions conference, which occurs annually. My whole family has taken fermented cod liver oil since 2007, and because of our years of use and great satisfaction with this product, I was more than willing to represent their company at the conference when asked by the owner, David Wetzel. I don't believe the fact that I work for the company is a conflict of interest since my family began consuming the product for years prior to my commitment.
Jarrod Tishhouse says
I'm interested as to why you recommend Nordic Naturals. Doesn't WAPF not recommend that one because it has synthetic vitamins in it?
Jenny says
No, to my knowledge, no synthetics are added to Nordic Naturals Cod Liver Oil. In fact, I just pulled a bottle from my fridge, and the ingredients were listed as: purified arctic cod liver oil, natural lemon flavor, d-alpha tocopherol (which is naturally sourced vitamin E) and rosemary extract. So, if you were informed (by WAPF or another person) that their CLO has synthetic vitamins added, you were misinformed.
Brianna says
I would say yes, it is possible for you baby to react badly to CLO. I recently have some to my 6 month old and almost immediately she was coughing and had raspy breathing. She broke out in a rash and swelling all around her mouth and chin. I have not given her CLO since then, as I believe she had a reaction to it. I might try again in the future but will probably try applying it directly to her skin next time as it can also be absorbed that way.
Nimisha says
Is it possible for a baby to have a negative reaction to cod liver oil (CLO)? My exclusively breastfed baby is 9 months old and I recently started giving him 1/2 teaspoon, but he had a very strong reaction 3 times. He started choking, struggling, and refluxed. He has had a lot of reflux, despite trying all remedies and now I am wondering if it was due to me taking CLO.
ValerieH says
In the past I took Carlsons and Nordic Naturals. I am not able to deal with the taste of Green Pastures. I buy the FCLO/butter oil blend in capsules. I bought Rosita brand as soon as it was available. It has a very light taste. It is expensive. It's really hard to know how to compare all of these brands. I don't know whether Carlsons or Nordic Naturals takes some of the good stuff out for other products, like a big dairy skimming the cream from milk to make sour cream.
Megan @ restoring the roost says
I too take Carlson's fish oil like the other above posters and would like to know your response for how it compares to cod liver oil. I believe it has most all the same nutrients you mentioned above in the cold liver oil but perhaps there is a difference in brand quality
Jenny says
I'm not terribly familiar with Carlsons, and if I were you, I'd reach out to them to ask about how it's produced (I look for COLD processing) and whether or not the vitamins are naturally-occuring or synthetic. I know many people take Carlson's.
Donna Arrington says
Thanks Jenny. This is so timely for me since I have been advised by my dietitian to take and didn't know where to start.
Jenny says
I hope it helps you!
Joshua Hampton says
I understand that cod liver oil has many health benefits. I do take it myself. My question is this: How were you able to convince your child to take it? I can't make mine do so and I don't want to force them.
Jenny says
Oh ... He just takes it off the spoon now that we switched to evclo. The flavor is super light and mild. If your kids protest, you might apply it to their skin ad it can be absorbed that way too.
Tania says
Jenny: what would be the dosage for a 6-year old? Also, any tips to transitioning from a kid-friendly fish oil like Barlean's brand (smoothie texture) to this one?
Jenny says
I think I gave my son 1/4 tsp at that age. You might try to see if your children will simply take it off the spoon. 1/4 tsp isn't that much, really. But it can also be absorbed through the skin.
Alevtina says
Hi Joshua! Try to add CLO in freshly pressed orange juice. You will hardly feel the taste of CLO. Other juices don't do the trick. I do half an orange for my 5yo daughter. Although it takes more time than just "off the spoon" way 🙂
Catherine says
I read above that cod lover oil is superior to fish oil. (I have taken Carlson's fish oil daily for years now.) I see the benefits of the cod fish oil... But how does it line up against fish. Why is t better? I apologize if I overlooked the answer! Very curious, as I will switch if I have a clear understanding that cod is better.
Jenny says
We take cod liver oil, as opposed to fish oil, because of how it is processed and because cod liver oil includes naturally occurring vitamins (that vary in quantity depending on the season).
Ali says
"In his studies of isolated societies subsisting on traditional and native foods, Dr. Price noted that intake of fat-soluble vitamins like A and D (as well as E and K) exceeded modern intake of those same vitamins by about 10 times." I am having trouble finding this in NPD or any of his other writings. Could you point me in the right direction? Thanks!
Nancy says
Do you also take a Vitamin D supplement or do you think this CLO has sufficient amounts?
Jenny says
I take a D supplement when we're under the weather which is, fortunately, rare.
Shawn says
I will be a vegan for 2 years in July and would love to know if there is a plant based supplement that would deliver similar benefits. Thank you!!
Jenny says
Hi Shawn". I think you'll be missing several key components in cod liver oil that aren't found in vegan sources. EPA and DHA, preformed vitamin A (retinol) and vitamin D.
Natalya says
Jenny, have you had any experience with Carlson Norwegian CLO? I am a student, and $49 for 150 ml is not an option for me at the moment. Thank you for all your care in researching and sharing about these critical topics. - n
Tess says
Hello Jenny! I know that you used to recommend Green Pastures' blend of butter oil and cod liver oil (even a few days ago your link for CLO went to Radiant Life) and I was wondering if you still take the CLO in conjunction with high vitamin butter oil as Weston A. Price recommends. Is it just a change in which company you support or do you feel like the Corganics brand offers a more powerful supplement? I intend to purchase a form of CLO/BO soon for my husband and I was just about to purchase from RL when this post hit my inbox...now I'm not sure!!! 🙂
Jenny says
It often takes me forever to get links switched over. I mean, the nonprofit links on my shopping guide have been sitting unlinked for a couple years now ... Yikes! I think it's best to take what you feel worksbest for you. We haven't taken the fermented oil for some time, and strongly prefer fresher oils.
Tess says
Thank you so much for your response Jenny. I appreciate the resources and knowledge that you give. 🙂
Char Psych n Stats Tutor says
I put it on my skin once or twice a week at night, great skin tonic and absorbs into blood stream. This treatment has removed skin growths as well as fine wrinkles. I also use on my dogs eyes for her cataracts, as the Vit A eats thru the growth.
Jenny says
Yes! It makes a beautiful balm.
Gail says
Can you put it in a human's eyes for cataracts?
Brie says
I don't understand how you used the oil for your dog and how much?
Darlene says
Thats amazing, but what do you mean by skin growths? And do you use fermented CLO?
Diane says
I'm wondering if there are any worries about heavy metals in cod liver oil like there is in other fatty fish? Or are they somehow able to remove any heavy metals from the oil?
Jenny says
I think most oils are regularly tested for heavy metal contamination, so it's not something I worry about.
Lj says
158 ml is equal to approximately 30 tsps.
Lj says
pardon, meant 150 ml.
Megan says
Once I spoke with GP customer service and the woman I was speaking to told me that hot weather (it was summertime in southern California) doesn't affect GP CLO and that she stores her's on top of her fridge.
I never had the time to look into the effect of fermentation on oils. Even though I know fermentation is one of the oldest ways to preserve food, I always thought that GP CLO had a slightly rancid taste.
I will give this one a try.
Jenny says
I think you'll find you like it.
Greta says
How long does the 150 ml bottle last when using 1 1/2 tsp a day ?
Christy says
Can you tell me how many servings are in each bottle (and is a serving 1/2 tsp or 1 tsp)? I looked on their website and can't find the information! I would love to switch to a higher quality oil since none of us can tolerate the FCLO, but need to figure out how many bottles I'd need a month for a family of 7 🙂
MelanieMiller says
What do you think about nutra pro virgin cod liver oil? I have thought about buying the evclo but we didn't do well on the fermented kind and my kids don't mind the nutra pro with peppermint oil in it...wondering how it compares?
Jenny says
I'm not familiar with that brand, so I don't have any experience to form an opinion.
Carrie says
Why not take the capsules for all of you that don't like taste of GP?
Jenny says
It's not just the flavor; rather, I can't stomach it, and I believe this offers higher quality fats.
Tina says
Taste aside, don't you think there is something lost in the fact that this CLO isn't fermented? Traditional peoples fermented their cod livers. Weston Price fermented his CLO that he used in his studies feeding poor children. I think there is something missed in this CLOs raw nature.
Jenny says
Tina, I spent a lot of time looking into CLO history, and traditionally cod liver oil wasn't fermented and kept for internal consumption; rather, fresher oils were used as food sources. The brown oils were used primarily for industrial purposes, or as lineaments, from what I understand. And keep in mind that even fermented cod liver oil isn't strictly produced through fermentation.
Further, it's a common misperception that fermented cod liver oil is what Dr. Price was using, but in reviewing Nutrition and Physical Degeneration, you'll see that there are absolutely no references to fermented cod liver oil in his work at all. Now, for people who tolerate fermented cod liver oil and are happy with it, they should continue to use it. For my part, I haven't been able to stomach it for some time and prefer the cleaner flavor of EVCLO.
Tina says
Obviously, if you can't get the fermented version down, I would view this as a second choice. Have you tried the getting your fermented CLO via the infused, flavored coconut oil by Green Pastures? The coconut oil is infused with a dose of not only fermented CLO but also skate liver oil. I personally love the cinnamon flavor. Based on the fact that the act of fermentation improves the nutrition of everything (cabbage, other veggies, kombucha, kefir, yogurt, etc.), logic would dictate that fermented CLO is likely the better choice if it can be tolerated.
Jenny says
I disagree, Tina. First remember that FCLO isn't a true fermentation and the production of it is simply likened to fermentation. I think this is a better choice (and Nordic Naturals). I worry about rancidity and oxidation in FCLO (and those worries may be unfounded) but I think we need to be wary of championing WAPF dogma hook line and sinker. I'm looking into having several oils tested for fat composition, vitamin A and D, as well as rancidity to hopefully present a picture that leaves out bias and gives us all fuller perspective.
Kim says
After extensive conversations with Dave Wetzel I understand that Green Pasture ferments the cod livers, not the oil. This would be in line with the process used by traditional Scandinavian people. Where is the information coming from that Green Pasture is not fermenting the livers?
Jenny says
Kim, it's my understanding that fermentation is a process that converts sugars into acids, gasses and alcohol. Since there's no sugar in liver, how is it possible that they actually ferment? I don't question whether GP processes their oils through traditional means. I question whether or not it is technically fermentation since fermentation is sugar-dependent. (I also don't think salamis and other similar meats are fermented as much as they are "cured" for similar reason.)
Kim says
Jenny, it is my understanding that the cod livers are "fermented" using a traditional method known as submerged culture fermentation. This was used by ancient people in preserving fish and other meats. It involves salt-tolerant, lactic acid producing bacteria. It is the glycogen in the liver that is actually broken down by the friendly microbes, which act to preserve the finished product. A by-product is the freeing or releasing of more oil than would result without the livers being fermented. The fat-soluble vitamin content is enhanced during the process.
I have used the FCLO with thousands of clients since it first became available and have seen consistently good results. As with any nutrient, more is not necessarily better and so we do not (nor does GP) recommend high dosages as this is a potent food.
The only time I have ever seen the FCLO/FSLO become rancid is if the bottle was opened and forgotten for a year or so in the back of a pantry. Of course, any oil will do this.
We are seeing a lot of robust conversations on this important subject. I think much of the confusion lies in the ideal that GP is fermenting their oils rather than the livers. It is the glycogen in the liver that is fermented, not the oil. Perhaps calling it "enhanced clo" would be more descriptive of the process.
Best to you!
Kim
avi says
Kim, I have a permanent illeostomy, colon was removed, and a history of breast CA, would love to start talking this oil as a suplement! Would you recommend it and what dose, I understand that if and when I begin, I'd have to slow down and then stop for a while.
Thank you and looking forward to your reply.
Ashley Portman says
Hi Kim - I am wondering if you can expand on the fermentation process of cod liver, specifically when you say "It involves salt-tolerant, lactic acid producing bacteria." What exactly does that look like? Is there salt being used in the fermentation process as we may lacto-ferment at home? Thanks!
amy says
This would be so interesting and beneficial. Has any progress been made on testing this? My husband is a biochemist and his first thought when I ordered FCLO was rancidity as I had a very strong reaction to it. Logic implied that it had to be rancid. However, I kept on believing what I had been reading about FCLO via the WAPF and other sources and kept trying to take it. I feel much better being off of it, but I would like to be able to understand rancidity in cod liver oils, plus the vitamin content.
Sandrine Love says
Tina, the livers are fermented. Most definitely fermented. The livers are fermented to extract the oils. The product could accurately be called "the oil of fermented cod livers" but, that is a long sentence, and David Wetzel chose fermented cod liver oil instead.
Sandrine Love says
I wanted to clarify that the oil itself isn't fermented. Oil can't be fermented.
Sandrine Love says
Hi Jenny,
It is correct that there were no references to fermented cod liver oil in Nutrition and Physical Degeneration. We only know that Price used "high-vitamin"' cod liver oil.
Sally Fallon Morell wrote to me today: "However, it is untrue that fermented cod liver oil was used for industrial purposes. We have a pamphlet dating from 1849 talking about "brown" cod liver oil and how it was superior to the pale cod liver oils for curing rheumatism."
Of course, I respect your decision to promote extra virgin cod liver oil. I think it is a valuable product. I just wanted to clarify this point.
Sandrine says
http://www.greenpasture.org/fermented-cod-liver-oil-butter-oil-vitamin-d-vitamin-a/historical-discussion-on-cod-liver-oil/
David Wetzel includes some .pdf historical documents.
Jenny says
Samdrine, are you not at all concerned with the likelihood of rancidity in the oils?
Sandrine says
Jenny, I am not at all concerned. I think you've been seriously misinformed, as I had been as well, based on results of a single test that Corganic sent to me, and their own interpretations of the results. I think that Extra Virgin Cod Liver Oil is a worthwhile product and am happy it is available to us but, I am not comfortable with their marketing approach, and the behind the scenes dynamics I've witnessed and experienced, which a number in our community has characterized as slander.
Since assertions of rancidity have been brought forward by Corganics, David Wetzel and Sally Fallon Morell have both tested fermented cod liver oil at different labs. No sign of rancidity of any kind.
Here are some of the test results:
http://www.greenpasture.org/utility/showarticle/?objectID=8899
http://bit.ly/1uoEFQP
http://www.greenpasture.org/public/Products/TestData/index.cfm
Statement from Sally sent to me this past week: "Dave has frequently tested his oil for all markers of rancidity, and there is no evidence of it in his oil. I also had it tested privately with the same results. To say that this cod liver oil is rancid and putrid is slander. You can post this. Sally"
Regarding Corganics' claim that Vitamin D2 is not in cod liver oil. Chris Masterjohn, PhD responds: "I don't see any evidence whatsoever that the USDA has this opinion. I see one person from USDA expressing this personally. The USDA guy quoted obviously has no idea what he's talking about. The vitamin D researchers who hate vitamin D2 spread this myth that D2 is not in the natural food supply, and is not in fish."
Chris Masterjohn will be writing an article about this soon. Sally Fallon Morell has tested 5 cod liver oils and will publish the results soon as well. It is very clear to me that fermented cod liver oil is not at all a rancid product. It is safe, some don't enjoy the flavor and/or don't tolerate it well. That's all.
Megan says
Sandrine-
Do you mean vitamin D3?
Vitamin D2 comes from mushrooms that have been exposed to sunlight. Some claim that it is *harder* to metabolize than D3-- so preferential (although both must be metabolized in the liver).
I don't know anything about Corganics' claim about vitamin D. But I have seen hard studies showing levels vitamin D3 is in fish and CLO. For example, we know that wild-caught salmon has about 3 times more vitamin D3 than farmed.
BTW, I showed the Nourishing our Children CD to my mother years ago and it was a real eye-opener. Thank you (:
Jenny-
Thanks for your response. Well put.
Megan says
Jenny-
Why do you think the FCLO is likely rancid?
I'm aware of what destroys polyunsaturated fatty acids (heat, light, air). Curious to learn more about the testing that you're doing and if you know anything (that we don't) about the storage and care of FLCO before its shipped out to consumers.
Thank you!
Jenny says
I think that the nose knows and one of the best indicators of rancidity is aroma and flavor, followed by how you feel after you've taken it. I felt good after having initially used a fermented cod liver oil, but over a period of years,I did not, so stopped taking it. (My son's experiences were similar.). I think I did well on it initially because my body was pretty starved for animals fats, fish fat and likely fat-soluble vitamins. So recently we started taking rosita extra virgin cod liver oil, and Nordic Naturals when rosita is not available) and there is a distinct difference in the freshness of flavor.
I'll post about the testing once it's complete (it's expensive, and the site already costs a mint to maintain), but oils will be stored according to manufacturer's specifications.
Abby says
I'm so glad I'm not the only one questioning Green Pastures FCLO as the only healthy CLO supplement. Of course, my reasons honestly have nothing to do with the science or research behind it. I just find it "fishy" when a product that is conveniently only produced by a single company is touted and a miracle health product and no other product made by any company anywhere could compare. I'm not saying that I think it is a bad product, just that I think taking FCLO is not the only way to health. Also, I love seeing someone questioning and doing their own research, thank you!
I take fresh ground flax seed and eat lots of homegrown pastured eggs for similar health benefits. People, remember, there is not just ONE miracle food that can bring health.
LB says
I would be very interested to learn the results of your tests on cod liver oil.
To be clear, I believe CLO is a valuable supplement to our diets. However, after reading widely about questionable practices in the supplement industry (see: Vitamania by Catherine Price, among others), I'm wondering whether these bottles of CLO actually contain CLO, given that there are no real regulations (read: independent verification or spot checks) on these items.
I've tried to find evidence of independent, third-party testing of various brands of CLOs, recommended by WAPF and others, and have encountered difficulties. Green Pastures, on its website, claims independent testing of its product, but it isn't clear who did the tests and how the tests were conducted and where. I worry that some producers are using -- theoretically, say -- canola oil with dye and flavorings that are being marketed fraudulently as CLO. The parallel is non-liquid supplements that were recalled recently because they were allegedly X herb, but in fact were nothing more than ground wheat with binders.
These are important issues for us all, not just in terms of money, but also in terms of ensuring safety and health for everyone, especially those of us who align ourselves with the principles of real food.
Sacheen says
This was very timely. I have been taking GP cod liver since Septemebr when my little one was found to have a cavity and he is not even two yet. I have been trying to get him to take it (I am nursing so hope he is getting some benefit through me) but he refuses. I am newly converted to the Weston Price ways and am always looking for information and ideas. I might try this brand for my little guy and see if he takes to it better. Thank you!
Jenny says
Hi Sacheen, you can also rub he cod liver oil into your little one's skin as it is absorbed that way, too, as far as I understand.
kira says
Hi..I was wondering how it worked out with your little ones cavity. My four year old just had a check up and he has a cavity but I don't want him to get the fillings and was looking to heal it with the GPS fermented cod liver oil and butter oil blend. Could I still heal it with a non fermented cod liver oil? Thanks so much for any suggestions.
robin noll says
My 7 year old had a cavity in one of his baby teeth, was told by our dentist that he needed a pulpectomy, (which is a root canal), and he would most definitely need braces in a few years. I had never heard of a CHILD needing a root canal! I went home and researched all I could as to WHY his teeth would be in such poor shape. Long story short, we joined a herd share and began drinking raw milk, eating raw butter, and taking cod liver oil. Now, he is 11 (almost 12), has BEAUTIFUL, STRAIGHT, CAVITY-FREE TEETH. Same for my 13 year old daughter. No cavities, no braces! I also have no problems with my teeth, after years of pretty bad tooth loss and gum recession despite brushing twice a day! My health is dramatically better on this diet!
Miriam says
Robin, that's great! Do you mean that the diet eliminated the need for the root canal, or did you have to do the root canal and his amazing dental health is after that?
Nina says
Robin, which cod liver oil were you using? The Rosita brand? Also did you all elimate grains as well or change your diet in any other way? Really curious to hear your results and experience! Thrilled that you were able to heal your family's teeth and now that I'm in the same boat, I'm trying to do everything I can to avoid getting work done.
Brooke says
Robin! I would love to connect with you more. I have terrible dental health despite brushing twice a day and flossing plus eating well. I can see where my four year old has a spot on her teeth and I am concerned for her dental health too. I am new to raw dairy but we have recently started and I got a book about curing cavities naturally. But I always love to hear and talk to real life folks! email me [[contact information redacted per comment policy]]
Mae says
Hi! I am currently a student and it's important to stay healthy! Do u have a suggestion however for a more budget conscious cod liver oil? I simply can't spend that much on cod liver oil right now! Thanks!
Jenny says
I think Nordic Naturals is also a good brand.
carri foss says
I believe NN is synthetic. Only Green Pastures and this one is the real deal.
Jenny says
No, NN is not synthetic. That said, I use EVCLO as my primary.
Jasmine says
I am going to try the nn brand. My question is regarding the iu's of vitamin D and A. They are very low. Is it enough to protect us during Michigan winters with very little sun? Adding this to our daily multi vitamin, probios and essential oils. And does it provides d3?
Kathy says
Maybe this one tastes better than the one I purchased. (Fermented Cod Liver Oil with Butter Oil Blend) I swear, I cannot tolerate it at all. Makes me sick and I want to throw up. It was expensive and sits in my refrigerator. Know I'll never use it. Can you tell me anything specific about this one and how it tastes.
Jenny says
I think it tastes very mild, clean with a flavor reminiscent of salmon sushi.
EWhite says
When my Mom gave it to us as children, it was always followed quickly with slices of an orange.
Ally @ Om Nom Ally says
I believe cod liver oil is hands-down the best supplement you could take everyday for building fantastic health. Thanks for this article, it's because of all these amazing benefits that I have taken cod liver oil for so many years 🙂
linda says
How does this oil compare to green pastures fermented cod liver oil?
Jenny says
I find that it tastes better, and makes me feel better than GP oil.
linda says
Thanks! I have to admit I am struggling with the GP CLO taste as I am 30 weeks pregnant. Do you think this brand would be safe to take in pregnancy too?
Erica says
My Midwife told me to stop fish oil, a vein supplement, etc. @ 36 weeks due to the blood thinning possibility being a risk for hemorrhaging during childbirth. They were all to be resumed right after the birth.
Julie says
Fermented cod liver oil led me to hemorrhage after giving birth. All was good - they got it under control quickly. But, I would listen to your midwife. I'm now a fan of non-fermented cod liver oil.
Sarah, The Healthy Home Economist says
There would be zero difference in hemorrhage risk between fermented cod liver oil and regular cod liver oil as this comes from the omega 3 fats which is present in both. Here is what the Weston Price Foundation says on the subject: "IMPORTANT WARNING: Cod liver oil contains substantial levels of omega-3 EPA, which can cause numerous health problems, such as hemorrhaging during the birth process, if not balanced by arachidonic acid (ARA), an omega-6 fatty acid found in liver, egg yolks and meat fats. Please do not add cod liver oil to a diet that is deficient in these important animal foods. It is important to follow our diet for pregnant mothers in its entirety, not just selected parts of it."
kim says
I am confused as some say don't take it and some say DO and that it is an important benefit during pregnancy? I love cod liver oil (not fermented, just lemon flavored oil) and I haven't stopped taking it even during my first trimester. I take half a teaspoon...is it bad? I feel really healthy with it.
Jenny says
I think it depends on the recommendations of your health care provider. Cod liver oil is recommended for pregnant women by the Weston A Price Foundation.
Tammy says
You might like Nordic Naturals lemon flavor. Very fresh with no fishy flavor.