Fish oil production does not simply turn out only one type of end product.
There are several grades of fish oil produced. The three essential types of fish oil produced today are categorized by their level of quality.
Cod Liver Oil
Cod liver oil, despite its historical popularity as a nutritional supplement, and a mother's cure-all, is considered as a low quality grade of fish oil. It may only be used in small amounts as an ideal supplement since this form of fish oil may contain certain contaminants. Cod liver oil is also known to contain high levels of vitamin A which can be toxic to humans in large doses.
One teaspoon of cod liver oil contains 500 mg of long chain omega 3 fatty acids. Cod liver oil contains the highest levels of contaminants which may include DDT, PCB’s as well as organic mercury. Taking this type of fish oil may not be safe in large quantities.
Health Food Fish Oil
Better quality grade fish oil is one that is sourced from a particular species of fish such as salmon. Most of these health food grade fish oil are usually available in soft gel capsules because they still carry with them a very poor taste profile. There is also a cholesterol free version of this type of fish oil grade.
This type of health food grade fish oil undergoes a slightly more purification process by means of limited molecular distillation in order to remove some of its cholesterol content in order to label it as cholesterol free. An even purified version of this health food grade version of fish oil is known as fish oil concentrate. This is the type of fish oil consisting of ethyl esters of the fish oil that undergoes fractional cooling. This allows a more purified form of fish oil with lesser amounts of contaminants that cod liver oil.
Generally, this type of fish oil contains a better concentration of omega 3 fatty acids. A single one gram capsule contains about 300 mg of omega 3 fatty acids. One capsule of a thermally fractionated health food grade can contain as much as 500 mg of long chain omega 3 fatty acids.
Pharmaceutical Grade Fish Oil
Pharmaceutical grade fish oils have been ultra refined in order to provide the highest quality of fish oil. This grade of fish oil undergoes through certain specialized processes in order to come up with the most refined fish oil. Certain specialized equipment is usually used in order to detect the minutest amount of contaminants in the fish oil. Because it is ultra refined, it is thousand times purer than the molecular distilled health food grade fish oils.
An ultra refined pharmaceutical grade fish oil contains more omega 3 fatty acids than the previous two fish oil grades. One gram of this type of product in a fish oil supplement contains around 600 mg of long chain omega 3 fatty acids. And for being the most refined of the three grades of fish oil, it contains the smallest amount of contaminants.