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I've been taking a couple of tablespoons of cod liver oil each day, but it was recently brought to my attention that the vitamin A levels in it could be a problem. Could anyone shed some light on this for me? I would really appreciate any input.

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The irony is that if you stuck with the pastured eggs from your other thread, you wouldn't need fish oil at all. In fact, you can get enough EFAs from 1 garbage egg and 1 omega 3 egg per day. – Travis Culp Dec 18 2011 at 22:21

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Excess Vitamin A is a problem when you are Vitamin D deficient. Check out this article which discusses this topic - http://chriskresser.com/9-steps-to-perfect-health-4-supplement-wisely

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Great article, hadn't seen it before...thanks! – Rogue Nutritionist Dec 17 2011 at 17:25
& Excess Vitamin D is a problem when you are deficient in Vitamin A, who would have thunk it. Recently discussed here paleohacks.com/questions/77024/… (Night Blindness) – daz Dec 19 2011 at 0:06
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Ummm, I definitely don't agree with Chris Kresser on this topic! (though I like a lot of what he writes...)

Here's another question on the topic: http://paleohacks.com/questions/1096/cod-liver-oil-and-vitamin-a-are-toxic#axzz1guv9AIzw

The ratio of Vitamin A relative to D in all cod liver oil is far greater what we would ever have gotten from our diet during our evolution. Often it is 20:1 and some CLOs may have more.

Think almost-naked living near the equator = 10,000-20,000 IUs Vitamin D per day plus maybe 10,000 IUs Vitamin A per week from liver/organ meats/eggs. So more like a 1:10 A:D ratio would be ideal.

There are other studies from Scandinavia that indicate that excess Vitamin A may compete with Vitamin D receptors and decrease the positive effects of D.

Also, for breastfeeding mothers, Vitamin D levels in the breastmilk do not increase enough to make sure the infant gets enough D from milk until the mother's blood level is at least 50 ng/ml, so his belief that levels over 50 ng/ml are not necessary makes NO sense to me at all. Sorry--I can't find the link to this one right now.

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If you are Not getting enough Vit A (for one reason or another) i would say its fine to take CLO, but just for the Vit A (ie. do not use as your source for EFA's or Vitamin D). 1 teaspoon (approx 4g or 4ml) = 2,500 IU Vitamin A. Make sure its natural CLO with no added synthetic vitamins. Basically you can ignore the Vitamin D in CLO (very small), & make sure you meet your EFA's, D & K2 requirements in other ways. & if you supplement with D, make sure its D3. – daz Dec 19 2011 at 0:04
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there may be other studies....but that particular study link (Vitamin A antagonizes the action of vitamin D in rats) was using D2 (ergocalciferol), not D3. – daz Dec 19 2011 at 0:04
Agreed, daz--and there are human studies, but I'm not finding my links today--time to rename my bookmarks! – Dragonfly Dec 19 2011 at 0:32

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