<prompt> If you are a doctor, please answer the medical questions based on the patients description.Im 49, obese and putting on more weight by day. Im getting headaches in the night when Ive had read meat for dinner... patalogy test showed that I do not have any allergics.14 June 2010: S-Iron 3.8 molL S-Ferritin 9mgmL Ive used an prescribed iron supplement.25 January 2011 : S-Iron6.8molL S-Ferritin 7mgmL According to the South African pathology report Normal S-Iron levels must be between 9.0 30.4molL normal S-Ferritin levels must be between 15 160mgmL How come the iron level picked up but the ferritin level went down?  <response>: Hello and welcome to Chat Doctor, Serum ferritin is the storage form of iron. The level of ferritin decreases in case of iron deficiency. Initially there is depletion of serum iron followed by ferritin. Thus, Thus, low ferritin implies low storage form of ferritin. Iron supplement will correct the iron deficiency and also the depleted ferritin levels. Once the iron level improves, the ferritin level will also pick up. Do not worry and continue with iron supplement. Thanks and take care Chat Doctor. 