According to The University of Maryland Medical Center, symptoms of vitamin B12 deficiency include tiredness, respiratory limitations, diarrhea, anxiety and tingling in the extremities. These symptoms arise from this particular vitamin not being replenished periodically by a protein-rich diet. In general, B vitamins are used to convert food energy into fuel for the body. A deficiency in these vitamins results in a lack of fuel.
Populations of people that are at risk for B12 deficiency include those with strict vegan diets and those that have issues with gastric food absorption. Harvard Health Publications claims that animal products avoided by vegans are sources of this essential B vitamin. Strict vegans who do not take pharmaceutical supplements or consume processed versions of B12 vitamins are prone to the symptoms of B12 deficiency. In addition, people who are not able to produce sufficient amounts of stomach acid to break down and absorb this B vitamin are at risk for a deficiency.
Once replenished in the body through diet, vitamin B12 is commonly used to form new red blood cells and protect the nervous system, according to MedlinePlus. Vitamin B12 collaborates with two other B vitamins called B6 and B9 to produce red blood cells. The neuroprotective effects of B12 are enhanced by its collaboration with vitamin B9 promoting compounds such SAMe which plays an active role in the human nervous system, according to The University of Maryland Medical Center.