Thiamine status was assessed by ARUP Laboratories (Salt Lake City, UT) via measurement of thiamin diphosphate (TDP, nmol/L) in whole blood samples. Red blood cell quantification of TDP, the biologically active form of thiamine, is thought to reflect total body stores: approximately 80% of thiamine in whole blood is found in the red blood cells and approximately 90% of thiamine in whole blood is in the form of TDP (Guerrini et al., 2009).
