Vit B12 deficiency causes neuropathy and encephalopathy
Low normal levels can cause symptoms or signs of disease so consider treating
Sources of B12 include meat and leafy vegetables
Syndromes
Replacement
Replacement can be done by injection, IM or SC, or oral. Oral doses should be 1 mg. a day.
Oral
In adults with normal absorption, oral dosing is equally effective as intramuscular dosing when given at a dose of 1000 mcg orally once per day. For individuals with impaired absorption of vitamin B12, therapy with very high oral doses of oral vitamin B12 (eg, 2000 mcg daily) will be effective as long as the dose is high enough to provide absorption via a mechanism that does not require intrinsic factor or a functioning terminal ileum (ie, passive diffusion/mass action). [1]
[1] R Means, K Fairfield. Treatment of vitamin B12 and folate deficiencies Uptodate
