Cod liver oil is the essential oil extracted from the livers of Atlantic cod.
The oil is often taken as a dietary supplement. It is one of the best sources of omega 3 fatty acids (EPA and DHA) and contains relatively high amounts of vitamin A and vitamin D. Because of these high amounts of A and D you shouldn't take too much of this good thing. I take less than a teaspoonful almost every day.
A controversy about cod liver oil has been stirred up because of an article that Dr. Joseph Mercola wrote on his popular website. The Weston A. Price Foundation responded to this article. The response seemed to me to be factual but it made me question some of my long-time-held ideas about this supplemental food that I've been taking for many years, and still take.
Potential health risks of cod liver oil
According to much recent research large amounts of fish and fish oil consumption can cause adverse side effects because of environmental toxins in these fish such as mercury and perhaps other heavy metals. I still eat fish but no more than once a week. It's too bad about this toxin issue because at one time fish used to be a perfect food - tasty and full of nutrients.
There is good information in this video without the hype.