These results were similar to other studies of anemia in the US population, including an analysis combining data from five National Health and Nutrition Examination Surveys (NHANES) from 2003 to 2012 (n = 41,026) which found the overall mean Hb was 14.2 g/dL, with 13.4 g/dL for female and 14.9 g/dL for male participants [29]. Here, GSTM1 is linked to anemia (phenotype).