An absence of a natural substance normally present in the stomach and essential to the digestion of vitamin B-12 . Lack of intrinsic factor leads to pernicious anemia and vitamin B-12 deficiency. Congenital lack of intrinsic factor causes inadequate absorption of vitamin B-12 starting around 6 months of age, while the juvenile type tends to manifest itself at an age greater than 10 years. There is an autosomal recessive inheritance pattern suggested in the congenital form.

Alternative Names

Addisonian (juvenile) lack of intrinsic factor; Congenital lack of intrinsic factor