halflife of B12?

[ChefJ]

Does anyone know the active half life of injectable b12??

[mkrulic]

Once bound with IF, vitamin B-12 is resistant to further digestion. The complex travels to the distal ileum and binds to a specific mucosal brush border receptor, cublin, which facilitates the internalization of cobalamin-IF complex in an energy-dependent process. Once internalized, IF is removed and cobalamin is transferred to other transport proteins, transcobalamin I, II, and III (TCI, TCII, TCIII). Eighty percent of cobalamin is bound to TCI/III, whose role in cobalamin metabolism is unknown. The other 20% binds with TCII, the physiologic transport protein produced by endothelial cells. Its half-life is 6-9 min, thus delivery to target tissues is rapid.

http://www.emedicine.com/neuro/bynam...l-diseases.htm

[ChefJ]

Once bound with IF, vitamin B-12 is resistant to further digestion. The complex travels to the distal ileum and binds to a specific mucosal brush border receptor, cublin, which facilitates the internalization of cobalamin-IF complex in an energy-dependent process. Once internalized, IF is removed and cobalamin is transferred to other transport proteins, transcobalamin I, II, and III (TCI, TCII, TCIII). Eighty percent of cobalamin is bound to TCI/III, whose role in cobalamin metabolism is unknown. The other 20% binds with TCII, the physiologic transport protein produced by endothelial cells. Its half-life is 6-9 min, thus delivery to target tissues is rapid.

http://www.emedicine.com/neuro/bynam...l-diseases.htm

This discusses ingested b12 I need to know about injected b12. How long it sits in the muscle or subQ area how long it takes to absorb and things. I guess I need to know if injecting it here and there will mess up ones blood levels.

[KAEW44]

some people inject as little as once a week and still get results, so i assume its more than a day...i personally am doing daily shots cause i'm addicted to giving myself the shots now.