The majority of research conducted with Onega-3 fatty acids has been done with fish oil, not flax, and has focused on the beneficial effects of EPA and DHA. Supposedly the human coversion of ALA (in
flax) is slow and only 15% converts to EPA, and 5% to DHA. Fish oils provide "preformed" EPA and DHA.

Opaque bottles, refrigeration, and added antioxidants or vitamen E should protect the delicate oils, as long as the source is good to begin with.

Most cod liver oil contains added synthetic vitamens A & D, but the rec. dosage of 1 tsp daily is safe. Nordic Naturals cod liver oil is the only one I've seen that only contains the natural vitamens A
& D that are in the fish, no synthetics are added. The amount of A & D in 1 tsp is below the USDA rec amounts.

1 tsp:
445 mg EPA
675 mg DHA
1915 IU Vit A
20 IU Vit D

also contains Vit E as a stabilizer, and natural orange essence for taste.

For what it's worth Dr. Price found in primitive diets amounts 10 times higher of A & D than what was in the typical American diet of his time.

I only take cod liver oil as opposed to fish oil because it's more economical. For those wanting to really pump up the EPA amount there are fish oils higher in EPA than DHA.

Laura Paris