Cod Liver Oil: Murky Contents

Triggered by an allegation of deceptive labeling, cod liver oil (CLO) has been the subject of several long running threads on a few mailing lists recently. The root cause seems to be the lack of transparency in labelling and production practises.

A post from October 2004 was the first indication that there was more than pollutants like mercury to worry about in cod liver oils. Petteri from Finland reported that the product information sheet filed with a government agency found soy product, synthetic vitamins and other additives in Carlson's cod liver oil.

Natural tocopherols (soy oil concentrate 70%), synthetic dl-alphatocopherol-acetate, retinylpalmitate-concentrate (incl. synthetic retinylpalmitate and peanut oil), cholecalciferol concentrate (incl. synthetic cholecalciferol and vegetable oil).
The lemon flavor version includes also: saccharinsolution (incl. ethanol), lemon flavor.

This vitamin E from soy is used to lengthen the shelf life of cod liver oil.

Petteri later asked Dr. Mercola (who endorses Carlson's cod liver oil) about these issues but received nothing concrete:

About a half year ago I contacted Mercola on the subject of Carlson's soy based vitamin E and the synthetic vitamin A and D used in the product. They asked for more information and after I send them some documents they went completely mute.

Recently, Pratick Mukherjee received a response from Carlson's many weeks after initially contacting Dr. Mercola. Timothy Johanek of J R Carlson Laboratories finally confirmed that Carlson's CLO contained soy-derived vitamin E. In a follow up, Johanek stated that a mixture of GMO and non-GMO soy was used, and no synthetic vitamin A or D was added. Unfortunately this contradicts Petteri's information sheet.

If that wasn't enough, the Weston A. Price Foundation stopped endorsing Carlson's Cod Liver Oil on their website in February 2005, stating "the manufacturer is removing vitamin A out of concerns of toxicity."

Removing nutrients is one thing, what about artificially increasing the levels of Vitamin A and D? There is concern among some that some CLO marketers may be engaging in this practise. For example, Petteri reports that a major CLO wholesale supplier, Lysi, cannot supply their product without fluctuations in vitamin content:

"We can offer unbleached and undeodorized cod liver oil with natural vitamins A and D. The vitamin content will however fluctuate a lot. The vitamin A can be approximately 600 - 1.500 i.u./g and the D vitamin 100 - 250 i.u./g."

Although producers may employ techniques to make vitamin levels more consistent, Petteri found that CLO marketers do not have to even bother, at least in his jurisdiction. In a conversation with a senior government scientist:

So I asked: If I add the required amount of synthetic vit. A and vit. D to a fish oil base, can I sell this procuct as cod liver oil? Would the Agency of Medicine approve it?

She said yes.

And would I have to mention the synthetic vitamins on the label?

No.

Another possibility is that the levels fluctuate in the actual product despite the implication of consistency made by the label, as Suze Fisher reported:

I have at least one assay of a batch from NF [Natural Factors] which I requested and it shows the peroxide value, as well as vits A and D potency, which can vary quite a bit from what the label states (on any brand).

Consequently, Petteri feels cod liver oils such as Nordic Naturals and Garden of Life's Olde World Icelandic, that state an approximate range, as more "honest" and convincing.

Fundamentally, it seems the companies that sell cod liver oil to consumers, the marketers, could do a better job of education and creating more transparency to their business. With a confusing plethora of terms, it's hard for consumers to know what is often-repeated myth and what's important. It is also ironic that a government-regulated informational filing in Northern Europe provided the first discussed hint of additives in one of the most reputable brands on the market.

Sometimes even the marketers aren't sure of the answers. Between fish and bottle is a mysterious process.