We raise the possibility that therapeutic interventions (such as improvement in nutritional intake, treatment of possible causes of lower levels of Hb, treatment of chronic conditions that may be impacting Hb levels, or pharmacological approaches to correct iron deficiency) may be taken with reductions of Hb levels, even before anemia is diagnosed, to maintain physical function, especially in older women. This evidence concerns the gene GSTM1 and anemia (phenotype).