Cod liver oil controversy
Something very odd is going on amongst alternative health circles at the moment, which is very amusing to watch as a disinterested third party. The “united front” in favour of cod liver oil seems to be exploding. First Dr. Joseph Mercola broke rank by stating he’s no longer using cod liver oil because of concerns about vitamin D toxicity. Then Anthony Colpo got all funny about vitamin A toxicity. Meanwhile the Weston A. Price Foundation have published their longest and most comprehensive article in the latest issue of Wise Traditions, defending vitamin A against the charge of osteoporosis. Though they all have different health philosophies, it’s unusual to see Mercola and Colpo breaking ranks with WAPF to this extent.
Personally, I think Mercola is being an idiot.
Cod liver oil is probably the safest form of vitamin D as it has vitamin A, which helps limit the vitamin D absorption if your levels are too high. However, it is my strong recommendation that anyone taking regular oral vitamin D, even cod liver oil, should have their blood levels checked.
You really need to be careful about all forms of oral vitamin D as it is just too easy to overdose. I had this personally confirmed this winter when I spent two months away from Chicago in a sub-tropical setting and had regular sun exposure nearly every day.
Prior to leaving, my levels were fine. When I returned, however, my vitamin D levels were in the toxic range, actually one of the highest we had ever measured at my clinic. I believe this was related to the fact that I was taking cod liver oil for two months prior to leaving.
I probably would have been fine, as I have been in past winters, if I wasn’t getting so much sun exposure.
Fortunately, elevated vitamin D from sun exposure drops relatively rapidly, but I am never taking cod liver oil again as I plan on escaping Chicago winters and regularly getting sun exposure year-round. ” Mercola
So let me get this straight: Mercola’s vitamin D levels were fine when he was taking cod liver oil before he went on holiday. Then on holiday he stopped taking cod liver oil and got lots of sunlight, and when he got back off holiday he had his vitamin D levels checked and his levels were “in the toxic range”. Mercola seems reluctant to admit it could be the sunlight. Probably because excess vitamin D is supposed to be destroyed by sunlight. And after all, we’ve been getting sunlight for millions of years. Mercola is forgetting that vitamin D toxicity only occurs under certain circumstances: when vitamin A levels are too low, when vitamin K levels are too low, and when calcium levels are too low. Perhaps he should have been paying more attention to his milk, yoghurt, and liver intake while he was on holiday. As someone who regards pasteurised dairy as “poison”, I wonder if he wasn’t getting enough calcium while away on his holiday?
Then we have Anthony Colpo saying things like:
like Mercola, I’m starting to back away from cod liver oil. Unlike Mercola, it’s not for reasons of vitamin D toxicity (I think vitamin D DEFICIENCY is a far greater concern for most folks, especially dark-skinned peoples) but because of vitamin A toxicity concerns. If people are eating a Paleo-style diet (i.e. meat on a daily basis) and taking a good multi, then vitamin A deficiency is a highly unlikely concern. This winter I won’t be taking cod liver oil, I’ll keep taking my fish oil and will also be supplementing with 1000IU per day of vitamin D3. The Omnivore
I think Anthony Colpo forgot that we don’t all eat 2 lbs of red meat every day like he does. Besides which, a quick search through the USDA database shows that red meat is not actually that high in vitamin A, the fat contains only around 40 i.u. per 100 grams. The vitamin A content of red meat is nowhere near the vitamin A content of butter or liver. Butter contains around 3,000 i.u. per 100 grams, your RDA, along with 30% of your RDA of vitamin D. To get a decent amount of vitamin A, you’d need to eat 100 grams of liver, which would provide you with around 30,000 i.u. Cod liver oil contains no more than 5,000 i.u. of vitamin A per teaspoon.
Acne sufferers regularly take in the region of 100,000 i.u. of synthetic vitamin A every day for as long as six months, experiencing very little in the way of “side effects” AKA toxicity symptoms. Vitamin A is actually a complex of several esters that occurs in nature with vitamin D. It is not pure retinol or retinyl esters. It works together with vitamin D and vitamin K and toxicity to some extent depends on the availability of vitamin D and vitamin K to the body, though it would not be wise to go thinking you can protect yourself from toxicity merely by throwing other vitamins into the ring.
Most of the original toxicity experiments performed on “vitamin A” were actually performed on synthetic/isolated compound acne medications like accutane. Accutane is not technically synthetic as it is produced in the body in small quantities. Accutane is known to have “a teratogenic potency in humans similar to thalidomide and rubella”, and was, along with other synthetic/analogs/isolated compounds of vitamin A incorrectly described as being “vitamin A” in moronic papers like this that cite manufacturer’s studies of artificial medications as being “vitamin A”, which they are not.
No studies on the toxicity of real vitamin A complex have been performed on humans. Comparable animal studies of natural vitamin A versus various artificial isolates differ wildly based on species (rat, mouse, hamster, rabbit, marmoset) and none have been performed on carnivorous animals, the only animals that are actually designed to consume significant amounts of preformed vitamin A!
Based on these acne medication studies the FDA then decided that *natural* vitamin A over 8,000 i.u. per day was therefore “toxic” and would mutate foetuses, and that pregnant women should get their “vitamin A” from beta-carotene. Traditionally women have eaten liver during pregnancy to ensure adequate vitamin A, which is required in significant amounts during pregnancy and lactation. A second scenario where vitamin A is required in large amounts is during puberty. Carotinoids convert poorly and inefficiently to vitamin A in the body.