Vitamin B12 defic anemia due to intrinsic factor deficiency

This code identifies megaloblastic anemia resulting from inadequate absorption of vitamin B12, specifically due to a lack of intrinsic factor. This deficiency prevents the body from properly absorbing dietary B12, leading to impaired red blood cell production and neurological symptoms. It is often associated with autoimmune gastritis.

Apply this code when documentation clearly states a diagnosis of pernicious anemia or vitamin B12 deficiency anemia explicitly linked to intrinsic factor deficiency. Supporting documentation should include laboratory findings confirming low B12 levels and/or positive intrinsic factor blocking antibodies.

• Distinguish from other causes of B12 deficiency anemia; ensure intrinsic factor deficiency is specified.
• Do not use for B12 deficiency anemia due to dietary insufficiency or malabsorption from other causes (e.g., gastrectomy, Crohn's disease) unless intrinsic factor deficiency is also documented.
• Consider sequencing with codes for associated conditions like autoimmune gastritis (K29.40, K29.41) if present and documented as the underlying cause.