Maj-
All that stuff was long before electronic media, which is why after I found it online I was so upset to lose it. But the bit I wrote (a few years ago to my sister) is pretty good from print sources and memory. Adelle Davis has a lot of it scattered in her books.
I just haven't been able to find that story again, as such.
Good place to start is here:
"A history of vitamin A and retinoids"
July 1, 1996 The FASEB Journal vol. 10 no. 9 1102-1107
and start searching the sources to see what turns up.
And a good overall review:
"Safety of Vitamin A" Bendich and Langseth
Am J Clin Nutr l989;49:358-71.
I personally am coming to the view that "toxicity" of V-A may be due to toxicity of OXIDISED V-A, and that can be prevented by C, D, E, and as I've found lately, iodine/selenium. Or, oxidation of V-A may deplete any/some/all of these, all of which are deficient in the general population, so that the "toxicity" is actually other induced deficiencies. Therefore high doses of some or any combination of these may be protective. This explains a lot of mysterious variation and apparently conflicting data, and might also apply as a principle to other "whole body" situations.
Owen - I did NOT say anything about cell differentiation above, but it does also apply. I was talking about maturation, and therefore function, of cells already differentiated.
Latest thought is that 1/6 of the proteome is in some way regulated by V-A. The Proteome is all the proteins produced by the genome AND their interactions, so is far more complex than the genome.
Here's a rather astounding study abstract (no full text access) involving V-A, folate, choline:
http://www.medical-hypotheses.com/artic ... 4/abstractThe above V-A toxicity report cites 200 cases of hypervitaminosis A/year, vs 1 million V-A deficiency, world wide. The cases of excess are clearly gross errors in part. From what I've seen virtually everybody except me has clear deficiencies sufficient to be noticeable, so I think the "deficiency" side is very much higher, likely several orders of magnitude. The annoying to life threatening effects of deficiency lead me to suggest that everybody increase their V-A, maybe not to my levels, but certainly to Pauling's. This is precisely the situation we know with respect to V-C, and I think numerous other nutrients. The deficiencies are sickening or killing far more people than any possible excess could or will.
FRM