Consuming cod liver oil has many benefits. It is a valuable source of the fat soluble vitamins A and D. Cod liver oil is also rich in the omega 3 essential fatty acids EPA & DHA which are vital for nervous and endocrine functioning.
There are some issues to consider if cod liver oil is to be used as a supplement. Some brands have been processed to remove natural levels of vitamins A and D due to concerns regarding vitamin A and D toxicity. Vitamins A and D or even synthetic forms of these vitamins can be added back by the manufacturer into the cod liver oil in different amounts to the original. This practice however results in an imbalanced cod liver oil which is no longer fit for consumption.
Vitamin A, Vitamin D and Cod Liver Oil: Some Clarifications
Critics of cod liver oil have focused on 3 concerns:
- Cod liver oil contains dangerous amounts of mercury and dioxins.
- Cod liver oil contains dangerous amounts of vitamin A.
- The vitamin A in cod liver oil interferes with the body’s assimilation of vitamin D.
Mercury and Dioxins in Cod Liver Oil
Cod liver oil is probably one of the cleanest foods in the food supply. All cod liver oil goes through a complete filtering process, and repeated testing has shown that the amounts of mercury and PCBs in cod liver oil are undetectable. For further information see cod liver oil processing
Even without modern processing, mercury in cod liver oil is not a concern because mercury accumulates in the protein portion of fish, not in the oil.
In addition, the vitamin A in cod liver oil is our best protection against dioxins. due to its antioxidant effect.
Vitamin A in Cod Liver Oil
The claim that vitamin A in cod liver oil is toxic just doesn’t make sense in the context of traditional diets, which were very rich in vitamin A from liver, organ meats, seafood and the fats of grass-fed animals. The crux of Dr. Price’s research is that the diets of healthy primitive people contain about ten times more vitamin A than modern diets. That is why cod liver oil is an excellent food source of vitamin A.
Over the years, the Weston A. Price Foundation has compiled extensive evidence showing that natural vitamin A in foods such as cod liver oil is not toxic EXCEPT in cases where vitamin D is deficient. That is why only certain brands of cod liver oil are recommended.
It is important to AVOID cod liver oil that contains low levels of vitamin D in relationship to vitamin A; the ratio of A to D in cod liver oil should be at least 10 to 1—unfortunately, in some commercial brands of cod liver oil the ratio is as low as 100 to 1.
Vitamin A and Vitamin D Interactions
The articles cited above show that vitamins A and D work synergistically, not antagonistically; if you take large amounts of vitamin A without vitamin D, you are likely to develop symptoms of vitamin D deficiency. Likewise, if you take large amounts of vitamin D without vitamin A, you are likely to develop symptoms of vitamin A deficiency.
The critics of cod liver oil seem to have very little understanding of how these vitamins work together. In fairness, very little study has been done on the interaction of A and D, although there is enough to show that A and D work synergistically. Recent research from Spain indicates that vitamin A is necessary for both vitamin D binding and vitamin D release to receptor sites. We will be reporting on this work in an upcoming article in Wise Traditions.
Once again, it is important to realize that traditional diets were rich in both A and D and that A and D have a myriad of uses in the body. Traditional peoples always had plentiful amounts of both A and D in their diets.
The Cod Liver oil Public Health Initiative
During the first half of the century, cod liver oil was the focus of a worldwide health initiative. Parents were urged to give cod liver oil to their children by doctors, by government officials, by teachers and principals in schools, and even by their ministers in churches. A large portion of adults in America born before the Second World War received cod liver oil as children and this practice contributed to a high level of health, intelligence and physical development in those lucky enough to receive it. In Europe and in many countries, children received a daily ration of cod liver oil, especially during the war years. In the UK, for example, the government issued cod liver oil to all growing children until the early 1950s.
What has led to the demise of this obviously beneficial practice? Cod liver oil is a food; it can’t be patented, it can’t be created in a laboratory; it can’t create millions for the drug companies. So interest in this wonderful superfood has naturally waned. But if you are basing your dietary habits on the principles of healthy nutritional diets, don’t hesitate to include cod liver oil—our recommended brands of cod liver oil--as a healthy and natural food source of critical vitamins so lacking in modern diets.
Weston Price Institute