Schuster K, Bailey L B, Cerda J J, Gregory J F
Am J Clin Nutr. 1984 Mar;39(3):466-70. doi: 10.1093/ajcn/39.3.466.
Urinary excretion of 4-pyridoxic acid (4PA) in 19 men (n = 5) and women (n = 14) was measured to evaluate the validity of determining the 4PA/creatinine ratio in random urine samples as an alternative to total 24-h 4PA excretion in assessing vitamin B6 nutritional status. The relationships among dietary vitamin B6 intake, 4PA excretion, plasma pyridoxal 5'-phosphate levels, and erythrocyte aspartate aminotransferase activity and in vitro stimulation by added plasma pyridoxal 5'-phosphate were examined. The subjects consumed all meals for 3 days in a metabolic unit, and protein intake was kept constant. Plasma pyridoxal 5'-phosphate concentration was positively correlated with vitamin B6 intake of the previous day (r = 0.61, p less than 0.01). There was a positive correlation (r = 0.59, p less than 0.01) between total 4PA and 4PA/creatinine in the 24-h urine samples. No difference (p greater than 0.05) in 4PA/creatinine between the 24-h samples and either morning or afternoon random samples taken the next day was found. These findings support the use of the 4PA/creatinine ratio in random urine samples as an alternative to 24-h urinary 4PA excretion.
对19名男性（n = 5）和女性（n = 14）的4-吡哆酸（4PA）尿排泄量进行了测量，以评估在评估维生素B6营养状况时，测定随机尿样中4PA/肌酐比值作为24小时4PA总排泄量替代方法的有效性。研究了膳食维生素B6摄入量、4PA排泄量、血浆5'-磷酸吡哆醛水平、红细胞天冬氨酸转氨酶活性之间的关系，以及添加血浆5'-磷酸吡哆醛后的体外刺激情况。受试者在代谢单元中进食3天，蛋白质摄入量保持恒定。血浆5'-磷酸吡哆醛浓度与前一天的维生素B6摄入量呈正相关（r = 0.61，p < 0.01）。24小时尿样中总4PA与4PA/肌酐之间呈正相关（r = 0.59，p < 0.01）。24小时样本与第二天上午或下午随机样本的4PA/肌酐比值无差异（p > 0.05）。这些发现支持将随机尿样中的4PA/肌酐比值用作24小时尿4PA排泄量的替代方法。
