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.
asked byDragonfly (32556)
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on September 05, 2012
at 03:45 PM
Seems to me that some folks do push the limit on Vitamin A/retinol, via supplementation with isolates or foods.
I know that many point to the poor conversion of BC to VA. The studies I've seen that show low-responders to BC also show that they have higher VA levels to start with. Should that really be so surprising?
on September 06, 2012
at 09:42 AM
it seems to me that the A to D ratio is important.
but know one really knows what it should be, either in the diet or in the body.
(& whether D means all the "D's" or just D3?).
Paul Jaminet suggests in his book that the maximum healthy ratio of A to D (from all sources; sun, food, supps) is no more than 3 IU to 1 IU.
Now, it would also seem that quite a few people on Paleo Hacks supplement with Vitamin D.
So as an example if we estimate someone's total Vitamin D intake as 4,000 IU per day, that would mean they could (safely?) intake up to 12,000 IU Vitamin A per day.
Also note that this is 12,000 IU of the animal form of Vitamin A (retinol) which equals 4 mg retinol.
It will equate to more than 4 mg in non-animal forms, ie. using the Linus Pauling Institute as a reference;
4 mg Vitamin A Retinol equates to;
.... 8 mg supplemental beta-carotene, or
.... 48 mg dietary beta-carotene, or
.... 96 mg dietary alpha-carotene, or
.... 96 mg dietary beta-cryptoxanthin
Another piece of info i read at vitamindcouncil is that "Vitamin A protects against vitamin D toxicity and visa versa but we don't know why".
on September 11, 2012
at 08:08 PM
My n=1: The lower left corner of my lip was dry/chapped/flaking all through the winter and spring, but it cleared up when I went on a two week trip without my supplements. I reintroduced supplements one at a time, and I found that when I reintroduced the Fermented Cod Liver Oil, my lower left lip swiftly became dry/chapped/flaky again, clearing up once more a few days after stopping the FCLO. I was taking the FCLO with butter oil and Vitamin D, but I'm persuaded that for me, my regular diet appears to have sufficient Vitamin A and the FCLO supplementary Vitamin A is harmful. If anyone has any possible accounting of the science behind this, however, I'm all ears--I can't figure it out.
on September 05, 2012
at 07:18 PM
I really don't understand the controversy.
Have you read all of the WAPF positions on Vitamin A, D, and K2? Especially Chris Masterjohn's articles?
(EDIT: removed comment regarding the quote at end of your posting - thought it was written by you)
So far I read one link by a group of doctors that likely think saturated fat is bad for us as well.
I will respond more once I can actually read the studies referred to in that ONE article you have posted.
part way through reading, here is an excerpt from the study that shows red flags over how you are interpreting it. In short, people were asked if they had smoked X cigs any time of their life, but only whether they took supplements in the past 30 days was considered. Furthermore, they DID NOT MEASURE dietary vitamin A intake, only supplemental. Which, by the way, we would guess that most supplemental forms are via B-Carotene...
Participants were asked whether they had smoked at least 100 cigarettes in life and whether they smoked currently to identify current and former smokers. For those who had smoked at least 100 cigarettes, number of cigarettes smoked per day, years of smoking habit, and years of quitting smoking were further queried. ... Participants were asked whether they had taken any vitamins or minerals in the past month and labels of supplements in the household were recorded. Those who took any forms of vitamin A and/or b-carotene supplements were identified as vitamin A/bcarotene supplement users. Dietary intake data for vitaminA were not used in this analysis because the single 24-h recall method used in NHANES III is unable to provide accurate estimates of usual dietary vitamin A intake due to its high day-to-day variability
on September 05, 2012
at 03:52 PM
Obviously n=1 does not a study make but I take a very high dose of vitamin A with FCLO (10ml) and shellfish, liver, etc. (I also take butter oil and a vitamin k2 supplement) My vitamin D levels consistently run between 65-75. When I drop the FCLO the only thing that happens is I start getting keratosis pilaris bumps on my skin... no matter how many colorful veggies I eat. I just really don't think this is a huge deal in people who are eating like we do. Many of the people on these forums who are reporting their blood tests are annually to bi-annually getting blood tests and are seeing good or at least rising levels of D. The average joe on the street is D deficient, mineral deficient, DHA deficient, etc.
on September 05, 2012
at 02:35 PM
Nobody in modern society is getting TOO much Vitamin A.
It just doesn't happen. It's like omega-3s. Nobody is getting too many omega-3s.
And I don't believe for a second that beta carotene can correct any sort of Vit A deficiency. Beta carotene is pretty useless as a source of Vitamin A and BC itself functions more as a plant antioxidant than animalform retinol. In addition, high serum levels of Vit A =/= adequate levels of Vitamin A in the body.