first start taking
B12 injections daily for 1 week then take it weekly for 1 month and then once a month for 1 year . after u can take it on yearly bases.
Next Steps
consult physician and your work up for the causes
b12 deficiency will be started including dietary habits, Long standing diarrhoea, Intrinsic factor test.
Health Tips
take dairy products n green leafy vegetables n nuts and eggs n chicken if u r a non vegetarian.