Lack of intrinsic factor

Alternative names:

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

Definition:

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.