B12 deficiency can damage your nervous system with a completely normal blood count. In a landmark NEJM study, 28% of patients with neuropsychiatric B12 damage had no anemia or macrocytosis. B12 runs How Quickly Does a B12 Shot Work? Benefits & What to Expect Vitamin B12 Injection Dosage for Adults: 7 Key Facts & Guidelines Liv Hospital Vitamin B12 Deficiency: Signs & Symptoms Vitamin B12 is essential for nerve health, red blood cell formation, and brain function. When B12 levels are low, symptoms often develop slowly and silently, B12 Injection Frequency: How Often Should You Get a B12 Shot? Liv Hospital