Other groups who may benefit include: Patients following gastric surgery (gastrectomy, bariatric procedures) where intrinsic factor production or absorption sites are compromised Individuals with malabsorption disorders such as Crohn's disease, coeliac disease, or chronic pancreatitis Strict vegans and vegetarians with dietary insufficiency, though oral supplementation is usually tried first Elderly patients with atrophic gastritis or reduced gastric acid production Patients on long-term metformin or proton pump inhibitors, which can impair B12 absorption [6] [8] Individuals with nitrous oxide exposure (recreational or medical), which can cause functional B12 deficiency Diagnosis typically involves serum B12 measurement, with levels below approximately 148 pmol/L (though thresholds vary between laboratories) generally indicating deficiency

Third, individual variation is substantial: patients with severe insulin resistance or significant mitochondrial dysfunction may respond at lower doses than metabolically healthy athletes
The current batch is independently HPLC tested above 99%, with online batch verification
These are statistically significant elevations
doi:10.1177/15648265080292S129
12 weeks 5 vials 84 daily draws