Comparison of methods for thiamin and riboflavin nutriture in man

Thiamin and riboflavin nutriture were assessed in 127 apparently healthy individuals aged between 20 and 82 yr, living in small villages near the town of Gubbio. The methods of erythrocyte transketolase activity and HPLC determination of thiamin pyrophosphate (TPP) for thiamin and erythrocyte glutathione reductase and HPLC determination of flavin adenine dinucleotide (FAD) for riboflavin were used. A significant correlation between enzymatic and HPLC methods was found. This was not the case for the correlation between status test and vitamin intake, particularly for thiamin. The vitamer determination in blood by HPLC can be considered a reliable, fast and reasonably accurate method for long-term thiamin and riboflavin nutritional status assessment.