GSTM1 and kidney disorder: Those with VAD were more likely to be of lower SES, have low prevalence of VDD, and suffer from anemia (due to inflammation and renal disease), low serum iron, high ferritin, higher status of inflammation, normal BMI, sarcopenia, cirrhosis, higher medication consumption, and higher serum levels of IL-6, CRP, EPO and lower Hb values in comparison with those OA with normal retinol levels (p < 0.05).