8.0 Anaemia iron deficiency anaemia IDA

anaemia

either the number of circulating erythrocytes (RBC) or haemoglobin (HB) conc contained within them are below reference range leading to reduced oxygen-carrying capacity

IDA means there is insufficient iron to meet the body’s demand for haemoglobin production

leading to reduced RBC formation an dimpaired oxygen transprot

iron is a crucial component of haemoglobin and without enough

the body can’t produce enough functional RBC resulting in anaemia

iron is stored in the liver + bone marrow as

ferritin

ferritin is a compound composed of iron molecules bound to apoferritin, a protein shell

the stored iron represents 25% of total iron in the body and most of this iron is stored as ferritin

ferritin is found in many body cells

but especially those in the liver/ spleen/ bone marrow and reticuloendothelial cells

when ferritin stores are depleted

haemoglobin synthesis is impaired

without sufficient iron the bone marrow cant produce healthy RBC

leading to small (microcytic) pale (hypochromic) RBC less capable of carrying oxygen

typical western diet contains daily intake of 15mg of iron

of which 10% is absorbed

approximately 20-25 mg iron is reuqired daily for RBC production

obtained from iron stores + recycled from old RBC after 120 within the ciruclation

causes of IDA

• inadequate dietary intake

• increase iron requirements

• blood loss

• malabsorption of iron

• chronic diseases

• medicines

inadequate dietary intake

insufficient iron in diet fails to meet daily requirement

increased iron requirements

pregnancy + lactation increases maternal blood volume creating a higher demand for iron 

growth spurts during infancy + hcildhood + adolescence also increase iron demand

blood loss

from heavy menstrual bleeding (menorrhagia)

gastric ulcers

colon + gastric cancer

haemorrhoids

surgery

haemorrhage or frquent bood donations

malabsorption of iron

coeliac disease / after GI surgery (gastric bypass)

iron absorption primarily done in the duodenum and proximal jejunum

chronic diseases

chronic kidney diease / chronic inflammatory disease

medicine

NSAIDs- due to potential GI bleeding

PPI- due to impact on iron absorption