Plasma B-6 vitamer and plasma and urinary 4-pyridoxic acid concentrations in young women as determined using high performance liquid chromatography.

Plasma B-6 vitamer and plasma and urinary 4-pyridoxic acid concentrations of 21 young white women, 21-27 years, having radiomonitored pyridoxal 5'-phosphate and coenzyme stimulation of erythrocyte alanine aminotransferase activities indicative of adequate vitamin B-6 status were determined in an effort to establish normal ranges for plasma B-6 vitamers. B-6 vitamers and 4-pyridoxic acid were quantitated using reversed phase high performance liquid chromatography with fluorometric and ultraviolet detection. Pyridoxal phosphate values obtained by radioenzymatic and chromatographic, fluorometric and ultraviolet, assays were highly correlated as were pyridoxine phosphate values determined using both detectors. The B-6 vitamer and 4-pyridoxic acid values of these subjects should be of use in the establishment of normal ranges of these congeners in women.

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

Plasma B6 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 B6 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 B6 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 mumol/mmol. All subjects had plasma PLP levels indicative of adequate vitamin B6 status. Vitamin B6 status parameters of the middle-aged obese black women were similar to those previously reported for white nonobese women having adequate vitamin B6 status.

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.

Plasma pyridoxal phosphate concentrations of men fed different levels of vitamin B-6.

The vitamin B-6 status of 12 white, 3 black, and 7 men of other races was evaluated utilizing plasma pyridoxal phosphate concentrations after the males had been on controlled diets for 8 wk. The diets contained averages of 1.22-1.67 mg/d vitamin B-6 as calculated from food composition tables. The actual mean vitamin B-6 content of these diets as analyzed with Saccharomyces uvarum was 0.75-0.98 mg/d; the mean daily protein intakes were 80.8-84.5 g. All subjects had plasma pyridoxal phosphate concentrations (67.6-125.8 nmol/L) well within the normal range; the values of the different race and dietary groups were similar. Vitamin B-6 requirements were satisfied by the consumption of diets analyzed to contain means of 0.75-0.98 mg/d of the vitamin as demonstrated by plasma pyridoxal phosphate levels indicative of adequate status. Dietary vitamin B-6 intakes should be determined by actual analyses when requirements are being determined.

Vitamin B6 status of a group of preschool children.

The vitamin B6 status of 35 preschool males and females was evaluated using plasma pyridoxal phosphate levels. The kilocalorie, protein, and vitamin B6 intakes were also estimated. Height and weight values of the three and four year old volunteers were within normal ranges. Seventeen percent of the children had estimated vitamin B6 intakes less than 2/3 of RDA. The estimated B6 intakes and plasma pyridoxal phosphate levels of children who took vitamin supplements were significantly higher than values for subjects not taking supplements. The plasma pyridoxal phosphate levels of children reportedly consuming less than the RDA for vitamin B6 were significantly lower than those of subjects consuming higher levels. Of the children 9% seemed to have inadequate vitamin B6 status as indicated by their having plasma pyridoxal phosphate levels below 8.5 ng/ml.