Fasting venous blood samples (15 mL) were obtained to estimate the hematologic
and vitamin status. Blood specimens were collected in Vacutainer
tubes (Becton Dickinson, Rutherford, NJ, USA) that contained EDTA as an anticoagulant
or that contained no anticoagulant as required. Serum and plasma
were prepared after centrifugation (3000g, 4C, 15 min) and were then stored at
80C until analysis.