Table 2: Plasma xanthurenic acid (XA) and pyridoxal-5′-phosphate (PLP) concentrations at the end of the vitamin B6-deficiency stage (−VB6−) and the other three stages of vitamin B6: normal (+VB6+), recovery (−VB6+), and excess (−VB6++).

Plasma XA (ng/mL)Plasma PLP (pg/mL)

+VB6+
−VB6−ND
−VB6+
−VB6++

Data represent the mean ± SD of seven replicates with three independent experiments. Significant difference was indicated with different letters ().