Abstract
We studied vitamin B1 (VB1) intake in some farm workers (26 men and women living in H-cho, Fukuoka Prefecture) said to have a comparatively high carbohydrate intake, and asked them to eat VB1-enriched rice over a long period to examine its effect through determination of thiamine levels and transketolase activity in blood. 1) VB1 intake, allowing for loss during cooking, was 0.67±0.20mg for males and 0.60±0.21mg for females, the rate of intake relative to the standard requirement being low (72.2±25.7% and 89.5±30.8%, respectively). 2) The level of thiamine was significantly improved from 23.3±5.8ng/ml before feeding to 42.5±7.9ng/ml thereafter. 3) The proportion of increase in the thiamine level after intake of VB1-enriched rice was 192±70% compared with that beforehand. Examination of the dietary contents of three groups, showing high, moderate and low degrees of increase, revealed significant differences in rice intake, celeals energy ratio, and protein energy ratio. 4) A positive correlation was noted between the level of thiamine and the intakes of protein and Ca, and negative correlations were noted between the serum VB1 level and alcohol (in terms of ethanol) for males and between the serum VB1 level and glucide and cereals energy ratios for females. 5) Examination of dietary contents in terms of the proportionate increase in thiamine level confirmed the usefulness of eating VB1-enriched rice especially in a group with a high rice intake and a low protein energy ratio.
