Since body stores of vitamin B12 are adequate for up to five years, deficiency is generally the result of failure to absorb it. Pernicious anemia, Crohn's disease and other intestinal disorders are the most frequent causes of vitamin B12 deficiency.
	Symptoms are attributable primarily to anemia, although glossitis, jaundice, and splenomegaly may be present. Vitamin B12 deficiency may cause decreased vibratory and positional sense, ataxia, paresthesias, confusion. Treatment of vitamin B 12 deficiency anemia. Intramuscular, oral or intranasal preparations are available for B 12 replacement.