You’ve certainly heard the buzz about cod liver oil (CLO). If you’ve been a crunchy mama for more than a minute, you’ve read about the amazing everyday benefits of adding cod liver oil to your AND your little one’s regimen. Indeed, cod liver oil has a host of benefits when supplemented daily.

The History of Cod Liver Oil

Cod liver oil has a long history, dating back to the 19th century when it was commonly used in fishing communities across Norway, Scotland, and Iceland. People in these regions endured harsh winters and long periods of darkness and turned to cod liver oil for its health benefits. By the late 1800s, it was widely used to help with rickets—a condition caused by severe vitamin D deficiency—especially in malnourished children. Adults also relied on it to help with joint health.

What Makes Cod Liver Oil Special?

Cod liver oil is rich in essential nutrients, particularly omega-3 fatty acids, which are key to supporting overall health. These omega-3s—EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid)—are well known for supporting heart, brain, and eye health.

In addition to omega-3s, cod liver oil contains important fat-soluble vitamins like Vitamin A and Vitamin D. According to Jordan Rubin in his book The Great Physician’s Rx, cod liver oil contains more Vitamin A per unit weight than any other common food source, making it a valuable supplement for those who may not consume enough through diet alone.

There are four main nutrients in cod liver oil that are frequently discussed for their health benefits:

• Vitamin A: Important for vision, skin health, and immune function.
• Vitamin D: Crucial for bone health and immune support.
• DHA: Supports brain and eye health, especially during development.
• EPA: Helps reduce inflammation and supports heart health.

You might need Cod Liver Oil if . . .

• You want a healthier immune system
• You have a family history of heart conditions
• You struggle to regulate your blood sugar
• You have stiff and painful joints
• You are a growing child
• You are experiencing mental fatigue or other mental symptoms

Benefits of Cod Liver Oil

• Immune Support: The combination of Vitamin A and Vitamin D in cod liver oil supports healthy immune function by helping to maintain the body’s natural defenses. (1)(2)(3)(4)
• Heart Health: A handful of studies suggest that cod liver oil may help support balanced triglycerides and blood pressure, as well as support overall cardiovascular health. (5)(6)(7)(8)
• Blood Sugar: Studies have shown that supplementation with cod liver oil can help improve glucose and insulin levels in the blood (9)(10).
• Joint Health: The anti-inflammatory properties of omega-3s may provide relief for individuals with arthritis or other inflammatory conditions. (11)(12)(13)(14)(15)
• Bone Health: With its high levels of Vitamin D, cod liver oil can help support strong bones, which is especially important for children’s development. (16)(17)
• May Help Balance Hormones, Fertility, Pregnancy, and Breastfeeding: Some research suggests that Cod Liver Oil can help balance hormones (18)(19)(20)(21)(22). It is the omega 3, vitamin D, and vitamin A with their anti-inflammatory properties of cod liver oil, that is believed can balance hormone levels involved with libido, sexual hormone production, and ovulation. Omega-3s are also the starting point for producing hormones (23).
• Supports Oral Health: Your dental health truly matters as they are an insight to what is occurring internally. The vitamins and minerals in cod liver oil can aid in dental health (24).
• Supports Skin Health: The vitamins in cod liver oil can help support skin health during recovery from wounds when taken internally (25). Vitamins A and D also support collagen’s life and longevity.
• Impact Discomfort during Headaches: Studies have found that diets rich in omega-3 fatty acids can impact discomfort from headaches and migraines (26)(27).
• Brain and Eye Health: DHA plays a critical role in brain development and eye health, making cod liver oil a beneficial supplement for both children and adults. Vitamin A and the Omega 3s are very important in eye and brain health with their anti-inflammatory properties and support of lining structure (28)(29).
• Supports Moods: Vitamin D and Omega 3s have been shown to support brain structures, metabolism, and cranial inflammation affecting one's moods. (30)(31)(32)(33)

Common ways to use Cod Liver Oil

When selecting cod liver oil, look for products that are cold-pressed and from sustainably farmed or harvested sources (ask for COAs). Avoid oils that have been highly processed, as this can destroy valuable nutrients. Avoid GMO-fed fisheries.

Available in:

• Liquid supplement
• Capsule
• Lotions
• Other skincare products

Fermented or Not Fermented?

This is a big debate, too large to fit into a tiny paragraph here. Basically, it isn’t fermented – it is rancid or putrefied if you prefer. It still has benefits because cod liver oil is that awesome, but it does not offer more benefits, being what some companies choose to call “fermented.”

How to take it?

The appropriate dosage of cod liver oil can vary depending on your age and health goals.

For Daily Maintenance for General Overall Support and Wellness:

• children (3 to teenage): 1/4 teaspoon daily
• adults (teens to adults): 1/2 teaspoon daily
• pregnant and breastfeeding women: 1 teaspoon daily

If the cod liver oil is cold-pressed, the taste isn’t as strong or unpleasant. It can be hidden in smoothies and milkshakes pretty well as long as a stronger flavor, such as mint, is mixed in.

Some say it is an acquired taste that may takes a while to get used to.

How Cod Liver Oil is Harvested

The quality and location of harvesting are especially important. The cod can be farm-raised or wild-caught. You should ensure the manufacturer is transparent about water quality if it is farm-raised. Even though you can get it farmed, it is best to get it wild-caught from the Arctic Circle. Be sure that it is also pure virgin cod oil for the best quality.

When the cod is harvested, the livers are separated from the rest and ground into a slurry with water. It then sits, and the oil rises to the top and then separates. You can get cod liver oil cold or hot processed. You want a high-quality cod that has been cold-processed. If not, the liver oil can become rancid and lose vitamins and minerals. You can also find fermented cod liver oil. However, in this case, fermented just means it's rancid or putrefied.

Safety Concerns

Drug Interaction: If you have any health concerns or are taking any prescription medication, please consult with your healthcare provider before adding new supplements to your diet.

Breastfeeding and Pregnancy: There are no known contraindications for breastfeeding and pregnancy.

Select Studies About Cod Liver Oil

Cod Liver and Depression

Cod liver oil has many benefits for mental health. This study examines its effects on depression. The study concluded that cod liver oil does relieve some symptoms of depression.

The Anticancer Effects of Vitamin D and Omega-3 PUFAs in Combination Via Cod-liver Oil

This study examines cod liver oil by studying how vitamin D and omega 3s in tandem affect cancer. Cod liver oil is one of very few natural sources that contains both nutrients.

If you are looking for a clean, cold pressed sustainably-sourced cod liver oil, then try Earthley’s Cod Liver Oil (available in liquid or softgels). We also use it to make our Vitamin D Cream!