Hi thanks for your question.
In 80 year old some amount of anaemia
is expected but you have to first rule out any pathological cause of aneamia that is bleeding some where from gastro intestinal tract or occult malignancy malignancy some wher in body .If any pathological cause of anaemia is ruled out then some amount of anaemia could be due to poor absorption of iron contained in food from intestine due to decreased blood supply which is normal process with age.Second reason coud be decreased erytropoitin production from kidney
(due to decreased blood supply) which stimulates the bone marrow
to produce red blood cell (RBC
) containing haemoglobin
.Third and final physilogical cause could be decreased RBC production by bone marrow.again due to decrease blood supply to bone marrow.If iron is not absorbed from ,increasing its dose will not improve haemoglobin.
I would suggest you to get your friend examined by internal medicine specialist who may be able to evualvate your friend for cause of anaemia and treat him accordingly
Hope this answers your question.