What is the Right B12 Blood Level

by NoName

i am a 40 year old woman suffering from short term memory loss and honestly i cant remember things in the past either . while my friends can remember things that we did together and places we ate at when we 15 .i also have other signs associated with b12 deficiency like tingly toes . my level is 453 which according to too the results 243 - 894 is normal . yet i have read that in china they consider under 500 for memory is low .