Symptoms of Vitamin B12 Deficiency

A deficiency of vitamin B12 can lead to vitamin B12 deficiency anemia. A mild deficiency may cause only mild, if any, symptoms. But as the anemia worsens it may causes symptoms such as:
weakness, tiredness or light-headedness
rapid heartbeat and breathing
pale skin
sore tongue
easy bruising or bleeding, including bleeding gums
stomach upset and weight loss
diarrhea or constipation

If the deficiency is not corrected, it can damage the nerve cells. If this happens, vitamin B12 deficiency effects may include:
tingling or numbness in fingers and toes
difficulty walking
mood changes or depression
memory loss, disorientation, and dementia

B12 deficiency in infants, if not detected and treated, can lead to severe and permanent damage to the nervous system. New mothers who follow a vegetarian diet should have their babies' B12 levels checked by a doctor