B12 is an exceptional vitamin. It is needed in lower amounts than any other known vitamin. Ten micrograms of B12 distributed in a day seem to provide all that the body is capable of using.
In the absence of any apparent dietary intake, deficiency symptoms generally take about five years or more to develop in adults, although some people experience problems as early as the first year.
A very small number of individuals without any obvious reliable source seem to avoid clinical deficiency symptoms for twenty years or more.
B12 is the only vitamin that is recognized not to be reliably provided by a varied, comprehensive plant-based diet, with plenty of fruits and vegetables, along with sun exposure.
Many herbivorous mammals, including cattle and sheep, absorb the B12 produced by bacteria from their own digestive tract.
B12 is found to some extent in soil and plants. These observations have led some vegans to suggest that the subject of B12 did not require any special attention, or even that it was a complicated hoax.
Others have proposed certain foods, such as spirulina, nori, tempeh, or barley grass, as suitable non-animal sources of B12. Such claims have not stood the test of time.
Who should be especially careful to get enough B12?
- Celiac people,
- People who abuse alcohol,
- People who abuse tobacco,
- People taking anti-cholesterol drugs.
What effects can its deficiency produce?
- Pernicious anemia,
- Neurological damage.
How are these effects manifested? What are the symptoms?
- Pain and weakness in the extremities,
- Decreased reflexes,
- Instability when walking,
- Lack of courage,
- Continued fatigue,
- Dementia in the elderly,
- Wounds on the tongue,
- Bad body odor.
Why can we be deficient in B12?
- Because our body does not absorb it properly (metabolic problems),
- Because we have kidney problems,
- Because we consume little B12 or little B6,
- For abusing coffee, alcohol or tobacco.