A slightly different take on the question than this one: http://paleohacks.com/questions/1096/cod-liver-oil-and-vitamin-a-are-toxic#axzz25bPKjtWe
I keep seeing folks recommending Cod Liver Oil (fermented CLO is especially popular) and wonder if they have really thought about the impact of the of high amount of Vitamin A in that supplement? Especially if they are already eating liver, butter, eggs & cheese weekly?
I'm not concerned about Vitamin A toxicity here, but how the high amounts of A some folks are consuming may be reducing their ability to benefit from a good Vitamin D status.
Some repeated info, but also a new study on lung cancer in this article:
"Expectedly, they found that “vitamin D sufficiency was associated with a 50-70% decrease in lung cancer mortality among nonsmokers.” Unexpectedly, to most, they found, “These beneficial associations were not observed among those with high concentrations of circulating vitamin A or users of vitamin A dietary supplements.”
A discerning comment at the end of the article:
Rebecca Oshiro said on August 31, 2012 at 2:31 pm
I gave a guest lecture on vitamin D to the July meeting of the Weston A. Price Foundation’s Seattle chapter last month. The cod liver oil debate is a touchy subject with them and one I was anxious to avoid, which inevitably came up. I now believe that the “miraculous” improvements Dr. Price saw with administration of cod liver oil to sickly American children and adults were due to the correction of severe nutritional deficiencies that were rampant in the first half of the last century. In Dr. Price’s time the population at large did not have access to an adequate diet, and as a result many suffered subclinical and outright nutritional deficiencies. The government knew this, and some of the earliest predecessors to the food pyramid (now MyPlate) had a special category for orange and yellow vegetables to encourage a higher intake of beta carotene. Greater access to these vegetables, along with more leafy greens, would have improved nutritional status to such a point there would have been nothing for the cod liver oil to correct.