Plasma B6 vitamer and plasma and urinary 4-pyridoxic acid concentrations of middle-aged obese black women

Abstract Plasma B 6 vitamer and plasma and urinary 4-pyridoxic acid (4-PA) concentrations of fifteen middle-aged obese black women were determined by high-performance liquid chromatography (HPLC). Estimated protein and vitamin B 6 intakes of the subjects, aged 27–52 years, were 64.5 ± 15.6 g and 1.21 ± 0.68 mg (mean ± S.D.), respectively. Mean HPLC-derived plasma B 6 vitamer and 4-PA concentrations for these subjects were 68.9, 3.1, 1.2, 4.1, 3.4, 7.2 and 2.0 nmol/l for pyridoxal 5'-phosphate (PLP), pyridoxine 5'-phosphate, pyridoxamine 5'-phosphate, pyridoxal, pyridoxine, pyridoxamine and 4-PA, respectively. The mean urinary 4-PA/creatinine ratio of the women was 0.88 μmol/mmol. All subjects had plasma PLP levels indicative of adequate vitamin B 6 status. Vitamin B 6 status parameters of the middle-aged obese black women were similar to those previously reported for white nonobese women having adequate vitamin B 6 status.