Vitamin B12

B12 is a water-soluble vitamin, also known as cobalamine, that is involved in the metabolism of every cell of the human body. It is an important vitamin that allows the nervous system to function properly because of its role in the synthesis of myelin and in the maturation of developing red blood cells in the bone marrow.

All humans, vegan or not, need to obtain enough B12 from their diet in order to be healthy. And all humans, vegan or not, obtain their B12 from the exact same source all animals obtain it: micro-organisms. That is because – contrary to what most people think – B12 is not made by animals, but by bacteria and archaea (microorganisms). Some of these bacteria are found in the soil and on the vegetables grown on that soil, but due to the use of pesticides and to our modern hygiene processes, the natural presence of B12 in vegetables is reduced and even eliminated. That means it is not objectively correct to claim that we cannot find vitamin B12 in vegetables: we could find it if we did not process vegetables the way we do it nowadays. Non-vegans obtain their B12 because they eat animal products that come from animals that obtained cobalamine from these microorganisms through their diet.

In order to obtain B12 eating a vegan diet it is necessary to consume cobalamine regularly. This can be done through vitamin B12 tablets, liquid drops or eating enough B12 fortified foods.

The most common cause of vitamin B12 deficiency in developed countries is impaired absorption due to a loss of gastric intrinsic factor, which must be bound to food-source B12 in order for absorption to occur. Another group affected are those on long term antacid therapy: using proton pump inhibitors; H2 blockers; or other antacids.

Vegans using adequate amounts of fortified foods or cobalamine are much less likely to suffer from B12 deficiency than non-vegans. Research on this area has found that 10 to 20 percent of older people may be unable to absorb B12, so it is advisable for those older than 50 years to meet their B12 intake by consuming fortified foods or vitamin B12-containing tablets.