Answer
Andrew does not obtain sufficient oxygen in his tissues due to the lower amount of hemoglobin in his blood, caused by the iron-deficiency anemia.
Hemoglobin has a very important role in respiration, as we can see in the reaction:
$$Hb(aq) + O_2(g) \leftrightharpoons HbO_2(aq)$$
Decreasing the concentration of one of the reactants, the equilibrium shifts in the direction of the reactants, decreasing the amount of oxygen that his tissues receives via $HbO_2(aq)$
Work Step by Step
Andrew does not obtain sufficient oxygen in his tissues due to the lower amount of hemoglobin in his blood, caused by the iron-deficiency anemia.
Hemoglobin has a very important role in respiration, as we can see in the reaction:
$$Hb(aq) + O_2(g) \leftrightharpoons HbO_2(aq)$$
Decreasing the concentration of one of the reactants, the equilibrium shifts in the direction of the reactants, decreasing the amount of oxygen that his tissues receives via $HbO_2(aq)$