Jim:
Just wanted to give you a little clarification on vitamins and livers. It’s not Vitamin D that has the problem with overdosing by eating livers. It’s Vitamin A, which builds up primarily in polar animal livers (not just Polar Bears- there was even a case of people overdosing from eating their sled dogs) because animals in polar regions tend to eat a lot of high fat fish.
Most bear livers won’t be a problem. I imagine that if you get a black/brown bear liver at the end of the Salmon run, and eat a lot of the liver that you might have a problem with it, but generally bear liver is safe. It’s actually not easy to overdose on Vitamin D from eating. I hope that clears things up. – Marty
Jim,
I read your blog today, especially the correction about polar bear livers. First of all, congrats for making the correction. The fat soluble vitamins are ‘KADE’.
And I was a bit confused at first. I recalled in US Air Force survival training that polar bear livers contained too much Vitamin A.
So, I did a little research. A general web search (Google) shows references to both A and D being the culprits. In researching the medical literature I found (but did not read) a very old article referencing Vitamin A: Toxicon. 1967 Jul;5(1):61-2. Vitamin A content of polar bear liver. Russell FE. PMID: 6036254 [PubMed – indexed for MEDLINE]
And this: As a carnivore feeding largely upon fish-eating carnivores, the Polar Bear ingests large amounts of Vitamin A, which is stored in its liver; in the past, humans have been poisoned by eating polar bear liver.http://en.wikipedia.org/wiki/Polar_bear Not exactly a very reliable source…
And finally, Air Force Regulation 65-5 (Survival, Training Edition) dated 15 July 1985, para 18-8 (a) (page 247) states:
” All animals in the arctic regions are edible, but the livers of seals and polar bears must not be eaten because of the high levels of vitamin A. Death could result from ingesting the liver.”
So, I’ll go with Vitamin A as the guilty culprit. Of course, I don’t understand why people eat any kind of liver….so it’s purely an intellectual question to me.
Keep up the good work, and the great blog. – Flighter