:shrug:yeah and sea greens actually can cause deficiency because its anolog b-12 takes up the receptor sites

According to Ronald Bradley who runs Hippocrates Australia: Cooked food vegans can suffer from B12 deficiency. Raw food vegans do not.

I have much research on the B12 controversy. Viewed as a whole it seems that we still have a long way to go before we come anywhere near a mature understanding of the science behind the B12 vitamin.

Some interesting snippets though:

An equal proportion of meat eaters suffer from B12 deficiency.

From memory, Doug Graham has observed improved B12 levels during extended fasting!

Probably the best discourse on B12 I have ever read come from the unlikely source of a cookbook:
"Classic Vegetarian Cooking" by Jean and Sue Easthope. I enclose the following snippets from it:

The process by which vitamin B12 is absorbed is unique among nutritional substances. The parietal cells lining the stomach wall secrete a substance, termed 'intrinsic factor', which combines with the B12, called "extrinsic factor', before this vitamin can be absorbed by the body. This combined complex then moves through the digestive tract to the ileum, the distant portion of the small bowel where it is grabbed by a group of receptor molecules located on the gut lining; these receptors seem to relish B12 and nothing else! The B12 is then bound to a protein transporter in the blood stream and carried to the many growing cells. Any unused B12 is excreted, mainly by way of the bile and so poured back into the intestinal tract. As the excreted bile passes through the ileum about two-thirds of this excreted B12 is re-absorbed and again made available to the body; a neat economical process.

The source of vitamin B12 is also unique. B12 is manufactured only by certain bacteria, a small number of moulds and a few other micro-organisms that occur in soil, ponds of water and even sea water, and their presence in these natural habitats leads to very low concentrations of B12 in the soil and natural springs. So animals browsing in the fields and drinking from streams and dams easily pick up adequate vitamin B12 for their daily needs. The carnivores, including meat-eating man, who use these animals for food, get their vitamin B12 by appropriating this material from what has been stored in the tissues of their victims.[/u]

Studies have been carried out on vegans of long-standing, and the results arc interesting. Over four to five years after adopting the vegan diet the reserves of vitamin B12 are gradually used up and the serum level of B12 stabilizes around 100 milligrams per millilitre, a level generally considered bordering on the danger line of low. But the test individuals were enjoying excellent health and not taking vitamin B12 supplements in their diet.

Of course, if we were not so inhibited by our excessive regard for cleanliness and hygiene, we would not be worrying about vitamin B12. The vegetarian cultures we have referred to have managed for centuries, but then they do not put their water supplies through chemical purifying processes and they don't scrub, peel and boil their vegetables as conscientiously as we do. Rhesus monkeys live on a fruit diet and in hygienic captivity they sometimes suffer from vitamin B12 deficiency, though they are healthy in the wild.[/u]

The primary cause of vitamin B12 deficiency is considered to be the lack of this particular vitamin in the diet, [u]but the secondary cause is more important— malabsorption of the vitamin. There are many causes for this malabsorption: relative lack of the intrinsic factor produced by the parietal cells of the stomach lining[/i[/u][/b]] as a result of disease and/or surgery of the stomach; diseases of the small bowel and, in particular, of the ileum, the principal site of absorption;


Good Health,
Neo.

"RawChef" on the eat.rawfood.com forums posted this link:

http://www.roylretreat.com/articles/b12.html

I am not sure how it measures up to the other information posted here.