Vitamin B12 – The Real Issue

In 1948 scientists stated with confidence that they had discovered the last vitamin, B12, based on the observation that it was possible to grow laboratory rats on diets composed only of chemically synthesised versions on these newly discovered food nutrients (“Whole” – T. Colin Campbell).

Vitamin B12 is made by bacteria in the soil and by microorganisms in the animal intestines, including our own. The problem is that the amount made by the bacteria in our intestines is not adequately absorbed. In the old days, muddy vegetables and spring waters were good sources of Vit B12 for our ancestors. Nowadays, we clean and sanitise thoroughly our vegetables, and our waters are treated with substances like chlorine to kill harmful bacteria like deadly cholera. These chemicals also wipe out the Vit B12 content in the waters. Therefore, we cannot rely on these sources anymore for adequate Vit B12 intake.  

Given our sanitary standards, a regular reliable source of Vit B12 is critical, If we follow a diet centred around plant foods (1). Vit B12 is a key nutrient for the correct functioning of the nervous system, brain, artery function etc…, so we must not take any chances. Although B12 stores in the body may take years to empty (2) (up to 3 years), the results of deficiency can be devastating with cases reported of paralysis (3), psychosis (4), blindness (5) and even death (6). Newborn infants of mothers who eat plant based diets and fail to supplement may develop deficiency much quicker with disastrous results (7). Therefore, Vit B12 supplementation is non negotiable for those centring our diets around plant based foods at any stage of our lives.  

So, we have three options to guarantee sufficient levels of Vit B12;      

  • Eat a small amount of animal foods on daily basis.
  • Eat Vit B12 fortified foods like cereals, soy-almond-coconut… drinks, or nutritional yeast, 3 times a day leaving at least 4 hour gap between each intake (8).  
  • Nutritional supplementation of Vit B12: 2,500 mcg of the Cyanocobalamin form once a week, or 250 mcg every day (9) (these doses are specific to cyanocobalamin).

Note: Any excess of Vit B12 that our body does not need, is eliminated through the urine.

Retrieve from Dr. Michael Greger’s book “How Not To Die”.
1-Pawlak R, Parrot SJ, Raj S, Cullum-Dugan D, Lucus D. How prevalent is vitamin B(12) deficiency among vegetarians? Nutr Rev. 2013;71(2):110-7.
2-Madry E, Lisowska A, Grebowiec P, Walkowiak J. The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study. Acta Sci Pol Technol Aliment. 2012;11(2):209-13.
3-Brocadello F, Levedianos G, Piccione F, Manara R, Pesenti FF. Irreversible subacute sclerotic combined degeneration of the spinal cord in a vegan subject. Nutrition. 2007;23(7-8):622-4.
4-Kuo SC, Yeh CB, Yeh YWY, Tzeng NS. Schizophrenia-like psychotic episode precipitated by cobalamin deficiency. Gen Hosp Psychiatry. 2009;31(6):586-8.
5-Milea D, Cassoux N, LeHoang P. Blindness in a strict vegan. N Engl J Med. 2000;342(12):897-8.
6-Haler Death after vegan diet. Lancet. 1968;2(7560):170
7-Roschitz B, Plecko B, Huemer M, Biebl A, Foester H, Sperl W. Nutritional infantile vitamin B12 deficiency: pathobiochemical consideration in seven patients. Arch Dis Child Fetal Neonatal Ed. 2005;90(3):F281-2.
8-Heyssel RM, Bozian RC, Darby WJ, Bell MC,. Vitamin B12 turnover in a man. The assimilation of vitamin B12 from natural foodstuff by man and estimates of minimal daily dietary requirements. Am J Clin Nutr. 1966;18(3):176-84.
9-Donalson MS. Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements. Ann Nutr Metab. 2000;44(5-6):229-34.

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