Vitamin B12: Are You Getting It?
A Vegan Health Article from

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This is the title of a scientific paper by Jack Norris, B.S. Nutrition Dietetics, who is Director of Vegan Outreach. It may be found on and is well worth reading – all 52 pages! I can here refer to only a few salient points. The author points out this is a first draft, not yet peer reviewed. [The comments in italics within square brackets are my own added gems! N.H. Fowler]

Vitamin B12 requirements

The Recommended Dietary Allowance of B12 is 2.4 µg per day and there is some evidence that 10µg is optimal. The average intake in the USA is 5µg/day.

Vegans should either

Take a daily B12 tablet (B12 on its own not mixed with other vitamins or minerals) or

 Eat at least two foods fortified with B12 on a daily basis – not just one like yeast or yeast extract.

Do NOT rely on seaweeds, algae, tempeh etc. Tablets are better chewed than swallowed. [Do not assume either that there is enough in your breakfast cereal or soya milk – many soya milks are not fortified so you need to check. Another thing, some cereal packets quote B12 for a serving including the assumed cow’s milk so be careful with the ‘small print’. Anyway the amounts they put in are very small.]

Long-time vegans who haven’t habitually done one or other of (a) or (b) should do (a).

[The most economical tablets in the UK seem to be Life Plan B12 25µg per tablet sold in containers of 100 for Ł1.55. If one takes half a tablet per day this will cost less than Ł3 per year. On the carton it says each tablet contains 2500% (25 times) of Daily Allowance, which seems to be working on a DA of only 1µg per day. Anyway, ˝ tablet covers even the higher 10µg. They contain no animal ingredients.]

Ensuring optimal B12 intake helps to ensure optimal health, possibly reducing the risk of heart disease and cancer. Some vegans retreat from the diet – is it because they have insufficient B12 and feel unwell whilst the one’s who are happy to stay with it and report feeling better for it are the ones getting enough for their needs?

Older people

10-30% of older people may malabsorb food-bound B12 because of lack of gastric acid or enzymes so it is advisable for those over 50yrs to have supplements or fortified foods. This applies whether they are vegan, vegetarian or flesh eating people. Elderly people should consider getting a Schilling test.

Where does B12 come from?

All B12 is initially manufactured only by micro-organisms, especially bacteria in soil and water and to an extent in animals’ guts. Animals mostly get theirs by eating food and drinking water contaminated with these micro-organisms. Plants do not need it so have no mechanism to produce or store it – that is why they contain little or none. B12 is found in all animal products. In food the B12 is bound to a protein (arrangement unique to B12) and digestive enzymes have to separate it before it can be absorbed from the Ileum – last part of small intestine. An adult vegan with absorption problems will exhibit deficiency in 1 to 3 years.

What B12 does

B12 is a co-enzyme. That is, it is needed for other enzymes to work.

It clears excess Homocysteine which is a nerve and blood vessel toxin. Without B12 the poison builds up and attacks nerves and blood vessels.

It produces a form of folate needed to make DNA and new cells e.g. blood cells and also the cells in the intestine that absorb B12 – thus a deficiency in diet becomes worse as absorption is also affected.

B12 depletion is measured in stages:

  1. Serum depletion
  2. Cell depletion
  3. Biochemical deficiency
  4. Clinical deficiency – megalobastic anaemia, nerve damage etc. [This is when it begins to show].

Symptoms of deficiency

  1. Earlier signs are tiredness, poor appetite or nausea, loss of menstruation, nervousness, numbness and tingling of the hands and feet, mild depression, striking behavioural changes, paranoia, hyperactive reflexes, unexplainable fever, frequent upper respiratory infections, impotence, impaired memory, infertility, sore tongue, and diarrhoea. If optic nerves are affected this will impair vision.
  2. Neurological; can be reversed in early stages but not later, leading to degeneration of the spinal cord.

Causes of deficiency

  1. Inadequate dietary intake
  2. Inadequate absorption due to problems in stomach, pancreas, ileum, liver, kidneys, taking diabetic drug Metformin or other drugs, auto-immunity to the intrinsic factor (IF) needed for its absorption.
  3. Inadequate utilisation – problems with enzymes, transport or storage proteins.
  4. Increased requirement e.g. Pregnancy or hypothyroidism.
  5. Increased excretion caused by alcoholism – but deficiency can also be masked because of release of extra B12 from damaged liver.
  6. Increased destruction e.g. by taking mega doses of Vitamin C, or Nitrous Oxide anaesthetic.
  7. Other medical drugs like cimetidine, metformin, potassium chloride, and cholesteramine.
  8. AIDS
  9.  Calcium shortage- eat plenty of dark green vegetables, broccoli, [sesame seeds, tahini, spinach, etc. – and remember you need Vitamin D to use the calcium – sunlight and/or fortified vegan margarine]. If you have to supplement use calcium citrate, lactate or gluconate, NOT carbonate which interferes with B12 absorption.
  10. Tobacco smoking.

Could high intake from supplements be harmful?

There appears little question that intakes of up to 1000µg per day are safe. [˝ tablet is only 12µg!]

How is the B12 in supplements obtained?

It is produced by bacterial culture and is acceptable to vegans.

Do vegans’ digestive systems make their own?

Yes, but too low down in the intestines, and it is mostly excreted [Some Iranian vegans were found to be growing their vegetable in ‘night soil’ and not washing them properly. Their B12 was okay! Personally I’d prefer a tiny tablet!]. There is a small amount in some vegetables, especially roots and better still if unwashed. Organic spinach is good but you would need to eat 1.6 kg (3.3 lbs) of the raw weight of it to get your daily need of 2.4 µg. – [34 lbs of it to get the equivalent of one tablet!]

There follows a review of many scientific research studies and case studies on vegans, other vegetarians and flesh eaters. Read about studies on vegans in England, vegetarian Indian immigrants, comparison of organic food with non-organic, vegans in Japan, babies, infants, Rastafarian vegans, children in Norway, Switzerland, Australia, Canada, Germany, France, Israel, New Zealand, Jamaica, Hong Kong, U.S.A., Seventh day Adventist Ministers, the Black Hebrews; read about vegans and heart disease, B12 and breast cancer, raw food diets, macrobiotics, and so on.


[For optimal health adequate B12 is vital. Deficiency can be very serious and may arrive insidiously. It is by no means just a vegan problem, in fact one study (A.M. Immerman 1981) plays down its importance for vegans, but vegan food sources are dubious. A vegan supplement is cheap, easy to take, and a pretty good insurance whatever else you do or don’t eat. There seems little reason, other than perhaps dogma, not to take it. A good varied vegan diet is the best diet possible, in our view, and shows significant health advantages regarding such major things as cancer, heart disease etc. not to mention BSE, Salmonella, Listeriosis, E. Coli, etc. For these reasons and also for the sake of the animals and the ecology of the planet it is necessary that more people adopt the vegan diet and stick to it. We can be more sure of continuing to be the healthiest people around, and avoid bringing discredit on the lifestyle, if we just look after our B12 levels. Please pass this message on to any vegans you know. Do not take my word for it – I cannot guarantee complete accuracy of this note – read the paper for yourself on the internet.]



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We began this archive as a means of assisting our visitors in answering many of their health and diet questions, and in encouraging them to take a pro-active part in their own health. We believe the articles and information contained herein are true, but are not presenting them as advice. We, personally, have found that a whole food vegan diet has helped our own health, and simply wish to share with others the things we have found. Each of us must make our own decisions, for it's our own body. If you have a health problem, see your own physician.