Assessment of Iron Status David L. Gee, PhD FCSN 442 Nutrition Assessment Laboratory 1

Iron Status Stage one - iron deficiency Depletion of iron stores Ferritin - primary storage form of iron Serum ferritin reflects tissue levels Low serum ferritin - early iron deficiency 16

Iron Status Stage Two Iron Deficiency Iron deficiency without anemia Transferrin - serum iron transport protein Serum iron reflects transferrin iron Each transferrin protein can bind two iron atoms 17

Transferrin Normal transferrin saturation (TS)= 30% Total Iron Binding Capacity (TIBC) add excess iron to serum to saturate transferrin, remove unbound iron, measure total iron = TIBC TS = [(serum iron)/TIBC]*100 low TS = stage 2 iron deficiency 18

Iron Status Stage Three Iron Deficiency Iron deficiency anemia low iron stores (low serum ferritin) low transferrin saturation microcytic hypochromic anemia 19

Hemoglobin Widely used diagnosis of late stage iron deficiency Table 9-6 cutoff values for Hgb based on 5th pct, NHANES II hemodilution during early pregnancy early exercise training 20

Hematocrit Packed RBC cell volume %HCT = % of RBC making up whole blood volume Manual measurement Automated blood counters calculated from RBC count and MCV high due to dehydration 21

Mean Corpuscular Volume MCV average size of RBC elevated with: folate and B12 deficiency decreased with: iron deficiency 22

Mean Corpuscular Hemoglobin MCH = amount of hemoglobin in RBC picograms per cell Mean corpuscular hemoglobin concentration (MCHC) average concentration of HB in RBC g/l 23