<prompt> Most sensitive indicator for Iron deficiency anaemia?Serum FerrtinTIBCPercentage saturation of transferrinBone marrow iron  <response>: Ref: CMDT 2019, P 512 Low ferritin levels 12ngml is a highly reliable indicator of reduced iron stores. Serum ferritin can increase in response to inflammation and hence normal or elevated ferritin level does not exclude diagnosis of IDA. As iron deficiency progresses iron levels will be less than 30mcgdl and transferrin levels rise to compensate. The elevated transferrin leads to lower saturation to 15. 