Research Supports Which of the Following Statements on Iron Supplementation

Research supports which of the following statements on iron supplementation?

A) If iron-deficiency anemia exists, iron therapy could help to increase physical performance
B) With iron-deficient, nonanemic subjects, iron supplementation will improve VO2 max
C) With normal hemoglobin levels, iron supplementation will improve VO2 max
D) High iron stores will increase the risk of CHD