When to Take Cod Liver Oil vs. Fish Oil

By Ben Kim, D.C.

If you have been a long time subscriber to my natural health newsletter, you know how important two omega-3 fatty acids, DHA and EPA, are to your overall health, particularly to your cardiovascular and nervous systems.

DHA and EPA are so critical to human health that I am convinced that high quality fish oil or cod liver oil should be a regular part of most people's diets.

My wife and I have been taking cod liver oil on a daily basis for the past few years in order to ensure adequate intake of DHA and EPA, and vitamins A and D.

This summer (2006), my wife is switching from cod liver oil to fish oil.

The major difference between cod liver oil and fish oil is that fish oil does not contain vitamins A and D. My wife and I decided that since she has been getting lots of sun exposure in the mid-afternoon these days, in order to ensure that she doesn't end up with too much vitamin D in her system from the sun and food sources combined, she will use fish oil to nourish her body with DHA and EPA until she is unable to get much sun exposure in the fall and winter, at which time she will switch back to cod liver oil.

I will be sticking with cod liver oil throughout the summer months because areas of my skin burn quite easily when I am out in the sun for long stretches at a time, so I usually stay indoors during the mid-afternoon.

In looking through my patient files from January of 2002 to December of 2005, I found 82 patients whose blood levels of Vitamin D I had records for. Eighteen of these patients were from Ontario, and the rest were from all over the States. Forty-eight of these patients were taking cod liver oil on a regular basis. And none of them, even those from California and Florida, had toxic blood levels of Vitamin D.

Based on the data that I have to go on as well as research that I have done on Vitamin D toxicity, I believe that most people are just fine taking cod liver oil throughout the year. However, I recommend switching from cod liver oil to fish oil in the following circumstances:

• During the warm summer months, particularly if your skin get lots of sun exposure and/or you eat lots of fish that are naturally rich in vitamin D, such as salmon, mackerel, and sardines
• During the warm summer months if you are pregnant or nursing
• Throughout the year if you live in an area where the weather is warm year-round and your skin is regularly exposed to sunlight
• If a blood test shows that your vitamin D level is greater than 50 ng/ml (125 nmol/l)

If you would like to switch from cod liver oil to fish oil during the warm summer months or even year-round, I recommend the same company that I recommend for cod liver oil: Carlson Labs in Arlington Heights, Illinois.

Just as it is with their cod liver oil, Carlson bottles their high quality fish oil in a way that ensures maximum freshness and nutritional potency. Their fish oil is regularly tested for potency and purity by an independent, FDA registered laboratory and found to be free of detectable levels of mercury, cadmium, lead, PCB's and 28 other contaminants.

You can order Carlson Fish Oil directly from Carlson Labs or from our web site using one of the following links:

Carlson Fish Oil 1 Large Bottle (16.8 ounces, 500 ml) of Lemon Flavored Carlson Fish Oil $32.97 (plus S&H)

Please note that I do not recommend fish oil or cod liver oil that come in gel capsules and/or plastic bottles. DHA and EPA are easily damaged with excessive processing and improper protection against oxygen and heat. High quality fish oil and cod liver oil are best bottled in thick glass containers.

Nutrient Profile for Carlson Fish Oil: