I read (in an blog that doesn't deserve quoting because it won't let me copy a single PHRASE to paste here) that in the FASEB Journal there was an article about retinol's role in ATP production. AHA! Then a short paddle around the PubMed pool revealed another wealth of information -- the author has done a LOT of work on mitochondria, our favorite organelle! ...Okay, okay -- they're ALL important....
It's going to take awhile to read and digest this information, but the starting-point is here: http://www.ncbi.nlm.nih.gov/pubmed/19812372 and the takeaway is this -- low retinol results in bare-minimal energy.
I also googled the factoid that 45% of people don't convert carotenes to retino's adequately; all in one place i got the (uncited) number i was looking for, PLUS material for thought.
Some people may not absorb adequate carotenes from the diet due to digestive problems and some people, even those with adequate thyroid activity, seem to have some difficulty converting the carotenes to the active form of vitamin A. In one study, up to 47% of British women were unable to adequately convert beta-carotene to vitamin A. The problem may be even worse in some populations.*Am i the only one who goes on point (the hunter-bitch that i am) at the notion that SOME PEOPLE ARE JUST NOT DESIGNED TO LIVE ON AN ANIMAL-FREE DIET? Some people do not convert this ABSOLUTELY ESSENTIAL nutrient from the form in which it's offered in the modern diet! Every time i see the title "foods that provide vitamin A" followed by a list of friggin' VEGETABLES (which have NO retinol content) i want to erupt.
But no time to read today! I'm teaching a class in tatting to a couple of dozen ladies at the Chatillon-de Menil House tonight, and i still need to print my hand-outs and collect my examples. :-) Later!!!
* see, i LOVE to give credit where it's due! it's the writers who are so friggin' scared that somebody's gonna STEEEEEAL their work that they make it really difficult to quote them AT ALL.... oh well -- this quote is from www.drlwilson.com/ARTICLES/VITAMIN%20A.htm