As a traditional concept, the mild metabolic abnormalities without clinical signs or symptoms are called subclinical cobalamin deficiency (SCCD), and it may progress to clinical symptomatic deficiency or remit completely without any signs
Standard oral supplements have poor absorption
Atrophic gastritis where the stomach lining becomes thinner
Kadara H, Choi M, Zhang J, Cuentas E, Canales R, Gaffney S, Zhao Z, Behrens C, Fujimoto J, Chow C, Kalhor N, Moran C, Rimm D, Swisher S , Gibbons D, Heymach J, Kaftan E, Townsend D, Lynch T, Schlessinger J, Lee, J, Lifton R, Wistuba I, Herbst R
You want maximum local tissue concentration for connective tissue support, which points toward subcutaneous injection near the target area or systemically
UpToDate (updated as of 2025).