The most important deficiency for the vegan is of vitamin B-12. By definition vitamin B-12 is essential to human life. It is essential for the synthesis of nucleic acids, the maintenance of the myelin sheath (the insulation around nerves which when damaged causes Multiple Sclerosis); indeed its presence or deficiency affects nearly all body tissues, particularly those with rapidly dividing cells.
Without it we suffer from pernicious anemia that, as its name suggests, is deadly, and a degeneration of the nervous system.
Vitamin B-12 is unique among vitamins in that while it is found universally in foods of animal origin, where it is derived ultimately from bacteria, there is no active vitamin B-12 in anything that grows out of the ground. Where vitamin B-12 is found on plants it is there only fortuitously in bacterial contamination.
Bacteria in the human colon make prodigious amounts of vitamin B-12. Unfortunately, this is useless as it is not absorbed through the colon wall.
Dr. Sheila Callender (13) tells of treating vegans who had severe vitamin B-12 deficiency by making water extracts of their stools that she fed to them, thus affecting a cure. An Iranian vegan sect unwittingly also makes use of the fact that human stools contain vitamin B-12.
Investigators could not understand how members of this sect remained healthy until their investigations showed that they grew their vegetables in human manure - and then ate the vegetables without being too fussy about washing them first (14) .
To enable vegans to survive, vitamin B-12 is added artificially to breakfast cereals in Britain and may be bought in pill form. This is hardly a natural way to get food and in many cases it is self-defeating. Vitamin B-12 is also unlike all other vitamins in that it occurs as a number of analogues, only one of which, cyanocobalamin, is active for humans.
In collecting human stools for analysis Dr. Victor Herbert found that of each one hundred micrograms of vitamin B-12 extracted, only five micrograms was of the cyanocobalamin analogue (15). Thus even in this most prodigious source of the vitamin ninety-five percent was composed of analogues that were useless.
Several fermented products such as tempeh, a soy bean product, and spirulinas, used by strict vegans as a source of vitamin B-12, either do not contain appreciable amounts of the vitamin or contain analogues of the vitamin which are not active for humans (16).
Vitamin B-12 status was assessed in a group of 110 adults and 42 children from a macrobiotic community in New England. Over half of the adults had low concentrations of vitamin B-12. Children were short in stature and low in weight. The community relied on sea vegetables for the vitamin. However, the researchers say: " We could not show that individuals who reported more of these sea vegetables had increased vitamin B-12 status…"
"Similar null results were obtained with the other sea vegetables, tempeh, and miso, foods considered to contain significant amounts of vitamin B-12 by many individuals in the macrobiotic community.
On the other hand, it is possible that the vitamin B-12 measured in these sea vegetables has no biological activity for humans…only a small fraction of total corrinoids in Spirulina, a genus of blue-green algae contains cobalamin and that the remainder is in the form of analogues that are not biologically active for humans. In these cases the analogues can block metabolism by the body of the ones that are of use."
Dr Herbert suspects that vegans taking the spirulinas as a source of vitamin B-12 actually bring on the symptoms of deficiency quicker.
Yeast is also believed by vegetarians to contain vitamin B-12 - and it does. But even if the yeast is grown on a medium rich in vitamin B-12, unless some of the growing medium is mixed with the yeast, it is unlikely to contain the cyanocobalamin analogue that is the active form for humans.
The amount of vitamin B-12 we need is very small: about five micrograms per day.
Eating more than is needed results in a reserve being built up in the body. When a person becomes a vegan, those stores are depleted - but only gradually. Thus it is possible to live for several years on such a diet before the onset of symptoms of deficiency. In England a carefully conducted study (17) carried out on vegans showed that they all got vitamin B-12 deficiency eventually.
The first manifestation of vitamin B-12 deficiency is usually mental disturbances. These range from abnormal mood swings, mental slowness and memory problems, through hallucinations and depression to severe psychosis.
Physical symptoms include: rapid heartbeat, cardiac pain, facial swellings, jaundice, weakness and fatigue and loss of weight. While a dose of active vitamin B-12 given by injection can cure symptoms very quickly, there is a hidden danger.
A largely vegetable-based diet provides large quantities of folic acid, which works in conjunction with vitamin B-12. In a diet that contains folic acid but is devoid of vitamin B-12 the folic acid can disguise the vitamin’s deficiency. In such a case, irreparable damage to nerves and the spinal cord can take place such that by the time symptoms become apparent, death is inevitable.