Go Vegan: Vitamin B12

Vitamin B12 or Cobalamin has a key role in the correct fonctioning of the nervous system and the normal production of red blood cells and DNA. 
Vegans can easily find all the vitamins and nutrients they need following their diet, except for Cobalamin. Why? 

No plants or animals (including humans) are able to produce it in their body, only bacteria have the enzymes for its synthesis. So how a omnivore can secure a proper amount of it daily? Only animal derived foods, like milk, cheese and eggs or animals' meat and fishes themselves have a good amount of vitamin B12, mainly because they have eaten and been in contact with 'bacteria contaminated' foods and soils. The impoverishment of cultivated soils and the aggressive use of pesticides and artificial fertilizers, combined with the excessive cleaning of harvested foods, it all leads to the sad consequence that fruits and vegetables we eat today provide no vitamin B12. That's why vegans could come across a deficiency of it, despite of the fact that it can easily be stored in our liver for years, just in case our supplies are scarce. So now, how can a vegan get a daily intake of Cobalamin? Unfortunately, just by taking supplements or eating industrially fortified vegetal food. By now, scientists have discovered no natural vegan-friendly source of it, so vegans have to come to a compromise in this case. Deficiency of vitamin B12 shouldn't be underestimated, because it could lead to serious health problems such as anaemia and nervous system damage. Typical symptoms include loss of energy, numbness, abnormal gait, sore tongue, poor memory, blurred vision, confusion, hallucinations, tingling, reduced sensivity to pain and personality changes. What's the daily intake recommended? It varies from 1.5 to 3 micrograms daily. You also have to take in consideration the fact that B12 is best absorbed in small amounts, so if you decide, for convenience or time reasons, to rely on a weekly supplement, it should contain around 2000 micrograms of B12, in order to equal the daily 3 micrograms intake.