Deficiency testing for iron, vitamin B12 and folate.

Dietary cells and the vitamins B12 and folate are necessary for the production of the red blood cells (erythrocytes), which carry oxygen from the lungs to the tissues and carbon dioxide from tissues to lungs. Deficiency of either one results in anaemia, which is characterised by low haemoglobin concentration. Symptoms result from reduced tissue oxygenation and include weakness, lethargy, palpitation, headache and shortness of breath. The first-time laboratory test of all patients suspected of being anaemic is the full blood count. Results of a full blood count may suggest the anaemia is caused by a nutritional deficiency of B12 folate or iron. Laboratory measurement of the concentration in blood of iron and vitamin B12 and folate, along with several other tests described here, are useful in the differential diagnosis of the anaemic patients.