The fastest way is to change your diet
And more necessary information you would expect to know
Inadequate secretion of intrinsic factor, resulting from lesions that destroy the gastric mucosa (which can be caused by ingestion of corrosives, extensive tumors, and conditions associated with gastric atrophy, such as multiple sclerosis, certain endocrine disorders, iron deficiency, and subtotal gastrectomy) Structural lesions leading to vitamin B 12 deficiency, including regional ileitis, ileal reactions, and malignancies Competition for vitamin B 12 by intestinal parasites or bacteria
If deficiency is linked to diet, improving B12 intake may help maintain levels
When stored under good conditions, unopened vials can normally last a few years