b12 injections and iron deficiency If you have an elevated HbA1c, you must also look into your Vit Profile Vitamin B12 Deficiency - Harvard
Description
Dosage Adjustments for Patients with Malabsorption People with conditions like celiac disease or Crohns disease might need more Vitamin B12

In particular, combining 2-OHNA with other NAD + biosynthesis inhibitors like FK866 effectively kills NAPRT-proficient cancer cells resistant to single-agent treatments 217

Tablet or injection, both are widely used
If fatigue is linked to low B vitamin levels, supplementation may help support energy production
