j code for b12 injection Does Procedure J3420 Require Prior Authorization? Should I Take B12 or

[1] Because intrinsic-factor-dependent uptake in the distal ileum can be absent in conditions such as autoimmune gastritis, pancreatic insufficiency, or bariatric surgery, the intramuscular or subcutaneous route bypasses gastrointestinal barriers and reliably restores serum concentrations

Oral absorption is considered too undependable to rely on in patients with pernicious anemia or other conditions resulting in malabsorption of vitamin B 12

If folate levels are low, folic acid should also be administered

Colchicine para-aminosalicylic acid and heavy alcohol intake for longer than 2 weeks may produce malabsorption of vitamin B 12