amount to give in b12 injection Vitamin Injections Dosage and Frequency B12 Injection Dosage and Frequency:

Common side effects include injection site pain, mild nausea, headache, and harmless reddish urine discolouration with hydroxocobalamin

N Engl J Med 368:149-60, 2013 6

But, we must figure out why it happened to avoid it coming back

These include: Neurological symptoms : tingling or numbness in hands and feet (peripheral neuropathy), difficulty walking or balance problems, memory difficulties, or mood changes including depression Haematological signs : persistent fatigue, weakness, pale or jaundiced skin, or shortness of breath Glossitis : a sore, red, smooth tongue Cognitive symptoms : difficulty concentrating, confusion, or "brain fog" Seek urgent medical attention if you experience rapidly worsening neurological symptoms, significant difficulty walking, severe paraesthesia, or marked cognitive decline, as these may require immediate assessment

So for the most common long-term situation, an absorption problem, maintenance means one injection every two to three months rather than anything weekly or monthly