Pernicious anemia, which is a B12 deficiency caused by the gut not able to absorb B12 from food, is one of the most missed diagnoses, especially in the elderly. Sometimes, a serum test will not pick it up, only a urine MMA test will, especially in th elderly.

Sometimes B12 injections can partly reverse the damage, sometimes not.

Ys, it can lead to death.

Was your doc negligent in assessing you, or did you jsut never go to see docs?

PA is a mimicker of MS.