Pyridoxal 5'-phosphate, pyridoxal, and 4-pyridoxic acid in the paired serum and cerebrospinal fluid of children Akiyama, T.; Hayashi, Y.; Hanaoka, Y.; Shibata, T.; Akiyama, M.; Tsuchiya, H.; Yamaguchi, T.; Kobayashi, K. Clinica Chimica Acta; International Journal of Clinical Chemistry 472: 118-122 2017 https://eurekamag.com/research/060/158/060158295.php