b12 injection for Are Shots Safe? Royal Palm Beach Medical Group Why Do You Need B12

If you have received injections for several weeks and notice no change, tell your provider

Inadequate secretion of intrinsic factor, resulting from lesions that destroy the gastric mucosa (ingestion of corrosives, extensive neoplasia), and a number of conditions associated with a variable degree of gastric atrophy (such as multiple sclerosis, certain endocrine disorders, iron deficiency, and subtotal gastrectomy)

If you increase dose and change timing simultaneously, you cannot determine which change affected results

However, persistently high serum B12 levels warrant medical investigation, as they may indicate liver disease, kidney dysfunction, or haematological disorders rather than simple overconsumption