Association Between 24 Hour Urinary α-tocopherol Catabolite, 2,5,7,8-tetramethyl-2(2'-carboxyethyl)-6-hydroxychroman (α-CEHC) and α-tocopherol Intake in Intervention and Cross-sectional Studies

The objective is to determine the association between the 24 hour urinary α-tocopherol catabolite, 2,5,7,8-tetramethyl-2(2'-carboxyethyl)-6-hydroxychroman (α-CEHC) and α-tocopherol intake in an intervention and a cross-sectional studies. In the 4-weeks intervention study, Japanese men (n = 10) consumed the test diet in week 1, and the test diet plus varying amounts of α-tocopherol in the three subsequent weeks: 21 μmol/d α-tocopherol in week 2, 63 μmol/d in week 3, and 125 μmol/d in week 4. A significant association between α-tocopherol intake and urinary α-CEHC was observed in this strictly controlled experiment (r = 0.99, p<0.001). In the cross-sectional study, all foods consumed over 4 consecutive days were recorded in 76 free-living young subjects (18-33 years). The association was weak, but a significant relationship was observed (r = 0.29, p<0.05) even in the cross-sectional study. In the cross-sectional study adults, mean estimated α-tocopherol intake calculated by urinary α-CEHC and the excretory ratio was 91% of their mean intake over the 4 days. The results show that urinary α-CEHC level reflected recent α-tocopherol intake in free-living young Japanese adults, and could be used as a measure of intake during the previous few days, both for group means and for individual rankings within a group.