Would you check vitamin B6 routinely in the work up of anemia?

I only consider it when I see ringed sideroblasts in the marrow. It is on the differential of things that lead to ringed sideroblasts. "Pyridoxine responsive anemia", which can be inherited or acquired. However, in my experience, it is very rare. Even the couple of people I have had with mildly decreased B6 in this situation failed to respond to replacement (anemia despite improved levels). If you do replacement, you need to monitor closely for response and stop if anemia does not improve. Long term use of B6 can lead to neuropathy and neurologic side effects. I have seen more patients with B6 side effects than actual deficiency leading to anemia.