D64.9 is a more general code for "Anemia, unspecified" and is used when the type of anemia (iron deficiency, hemolytic, vitamin B12 deficiency, etc.) is not documented
(PubMed) Powers CD, Sternberg MR, Patel SB, Pfeiffer CM, Storandt RJ, Schleicher RL
Clinically overt vitamin B12 deficiency, characterized by hematological and neurological dysfunctions, is relatively uncommon
Though not dangerous, these symptoms can be uncomfortable and may persist with continued high-dose usage
Its a massive public health victory
Oral Vitamin B12: Effectiveness and Most Beneficial Users Oral B12 supplements are common and simple to take