How do you manage B12 deficiency refractory to subcutaneous replacement?

I tend to start with IM injections of B12 when patients are severely deficient. The most common mistake in replacing severely low B12 is to not load, or to check levels too early. I have not used SQ administration before. It should absorb, but if you are having issues I would go to IM and start weekly x 4 and then repeat levels. You can also check MMA and homocysteine to see if this is truly deficiency. It's possible that your analyzer is being affected by intrinsic factor antibodies or other in...

Does the patient have subcutaneous edema?

I would administer IM unless there is a contraindication.