Vitamin B12 is the nutrient many medical doctors claim to be most difficult for vegetarians to obtain. It is produced only by microorganisms and thus found more often in animal-based products.
Vitamin B12 is required for red blood cell formation and normal growth, it is important for fertility and during pregnancy, builds immunity and treats some degenerative diseases, and it is used therapeutically in many mental and nervous disorders. More recently it has been used to energize the body and counteract allergens.
Vegans and Vitamin B12 | Signs of Vitamin B12 Deficiency
The earliest signs of B12 deficiency are weakness, listlessness, fatigue, diarrhea, depression, and indigestion. Other signs are paleness, numbness in the fingers and toes, heart palpitations, anorexia, shortness of breath, infertility, and mental imbalances including faltering memory, moodiness, apathy, paranoia, hallucinations, violent behavior, personality changes, and other derangements.
The tongue is an indicator of serious B12 deficiency. It becomes red, shiny and smooth, and is sometimes ulcerated. In the final stage before death, irreversible paralysis and brain damage occur.
Symptoms of vitamin B12 deficiency do not always show—they can be masked by the B-complex vitamin folic acid. Folic acid and B12 have certain similar functions, and each requires the presence of the other in many of their activities.
Anyone, vegetarian or omnivore, with weak digestion can become deficient in vitamin B12. In addition to poor digestive absorption, there are other specific factors that deplete the body of vitamin B12:
1. Birth control pills and antibiotics
2. Intoxicants (alcohol, cigarettes, coffee, and all others)
3. Stress from any source, especially from injury, surgery, or trauma
4. Liver diseases and chronic illnesses.
Vegan Sources of Vitamin B12
These include miso, soy sauce, tempeh, pickles, amasake, nut and seed yogurts, and sourdough (naturally leavened) bread.
Tempeh, a currently popular cultured soy product with origins in Indonesia, has some of the highest B12 content of any food (up to 15 micrograms of the vitamin in a 100-gram serving).
Scientific tests have shown a number of algae to be excellent sources of B12. In fact, microalgae such as spirulina and chlorella are considered some of the highest food sources of vitamin B12.
Certain macroalgae—nori, wakame, and kombu seaweeds—are sometimes touted as having significant B12 content.
Nutritional yeast has been used as a B12 source for vegetarians for more than thirty years. A problem with yeast is its very nature: microorganisms of this sort tend to induce unhealthy amounts of candida-type yeasts in the body, especially in individuals who are susceptible to Candida overgrowth. Find out more about it, here.
Protein and Vitamin B12 Sources
The B12 requirement is one to three micrograms per day for adults, if taken from natural sources, and it can triple if taken from supplements. Here is a table with the best vitamin B12 sources for vegans and their concentration.
Vegan foods with vitamin b12 – Table was taken from the book Healing with Whole Foods: Asian Traditions and Modern Nutrition by Paul Pitchford