"No one" is a couple of internists, my dad and my uncle (both doctors), and various random people I mentioned it to. What I mean is that people who know I used to be anemic and that I now have this dyspnea problem have never asked "I wonder if you still have [anemia-related subcondition] and that's causing the dyspnea?"

The iron pills working was confirmed with a blood test. Before I took iron pills, my readings on some relevant feature of my blood were so low that I ought to have been fainting on a regular basis; after they were in normal range and I've been allowed to give blood several times since.