intrinsic factor(redirected from Castle intrinsic factor)
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intrinsic factor[in′trin·sik ¦fak·tər]
A substance, produced by the stomach, which combines with the extrinsic factor (vitamin B12) in food to yield an antianemic principle; lack of the intrinsic factor is believed to be a cause of pernicious anemia. Also known as Castle's intrinsic factor.