Separation and quantification of the B6 vitamers in plasma and 4-pyridoxic acid in urine of adolescent girls by reversed-phase high-performance liquid chromatography.

The vitamin B6 status of seemingly healthy adolescent girls was determined using several accepted and proposed parameters in an effort to establish guidelines for status evaluation. High-performance liquid chromatography-derived plasma B6 vitamers (pyridoxal phosphate, PLP; pyridoxine phosphate. PNP; pyridoxamine phosphate, PMP; pyridoxal, PL; pyridoxine, PN; and pyridoxamine, PM) and 4-pyridoxic acid (4-PA) concentrations and urinary 4-PA levels of 28 white adolescent females, 12-15 years, having radiomonitored plasma PLP concentrations and coenzyme stimulation of erythrocyte alanine aminotransferase activities indicative of adequate status were determined. Mean vitamin B6 and protein intakes were 1.48 mg and 78.3 g. Ranges for plasma B6 vitamer and 4-PA concentrations (nmol/l) were: PLP, 40.9-122.2; PNP, non-detectable (ND)-16.1; PMP, ND-8.1; PL, ND-15; PN, ND-21.9; PM, ND-17.8; and 4-PA, ND-55.7. PLP was the only vitamer found in plasma of all subjects. Urinary 4-PA concentrations ranged from 0.11 to 2.50 mumol/mmol of creatinine. B6 vitamer values of these girls should be of use in the establishment of normal ranges for vitamin B6 status parameters.