I had blood test recently and have been told that I have very low levels of ferritin and that my “haemoglobin was zip" (?). Doc said to take supplements for 3 months and go back in to check it. I read somewhere that iron depletion can be caused by running. Does anyone know if this is true? In my case there were other causes, I’m just wondering if training will make things worse/slow down the improvement. Am running the half marathon at Silverstone (very slowly no doubt) so have a lot to do!