Normal absorption: 1000 mcg/day PO
Malabsorption: 100-1000 mcg IV/IM or deep SC injection daily for 6 or 7 days
Nasal spray: 500 mcg intranasally in one nostril weekly
Vitamin B12
Folic acid
Vitamin K
Thiamine
Niacin
Pyridoxine
Selenium sulfide
EDTA