- body stores last a few years (folate - a few months). thus if see macrocytic anemia, likely due to folate, not B12, deficiency
- clinical: DANGER, can cause neurologic deficiencies!
- a diagnosis of B12 def is FOREVER!
- causes: pernicious anemia (cannot absorb b/c lose gastric IF (nec for absorb) due to autoimmune damage), vegan diet, loss/def of terminal ileum
- clinical: palor w/ yellow skin, beefy red tongue, neuropsychiatric: paresthesias, sens loss, dmentia
- treat: Vit B-12 daily, then weekly until HCT is normal. then monthly for life!