vitamin C deficiency diminishes its effectiveness.33,34 Others have observed significantly reduced levels of ascorbate in transfused subjects.10,30 In addition, iron overload leads to an increase in non-transferrin– bound iron and a sequential re- duction in circulating antioxidants.35,36 In this study, adoles-
cent and adult subjects consumed few orange vegetables, foods known to be rich in antioxidants. In addition, the inad- equacy of dietary intake of key antioxidants (eg, vitamin E, C, and zinc) increased with advancing age. Some subjects, per- haps recognizing their diets were inadequate or who were