Clinical analysis of vitamin B6: Determination of pyridoxal 5′-phosphate and 4-pyridoxic acid in human serum by reversed-phase high-performance liquid chromatography with chlorite postcolumn derivatization

Rybak, Michael E.; Pfeiffer, Christine M.

doi:10.1016/j.ab.2004.06.036

Cited by 62 publications

(67 citation statements)

References 38 publications

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“…LOD varied from 0.1 nmol/L for PN to 4 nmol/L for PMP and FAD. The LOD values obtained were comparable to those of other B 6 (20,25,27,29 ) and B 2 (39 ) assays.…”

Section: Performance Of the Methodssupporting

confidence: 79%

See 1 more Smart Citation

Multianalyte Quantification of Vitamin B6 and B2 Species in the Nanomolar Range in Human Plasma by Liquid Chromatography–Tandem Mass Spectrometry

Midttun¹,

Hustad²,

Solheim³

et al. 2005

Clinical Chemistry

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“…LOD varied from 0.1 nmol/L for PN to 4 nmol/L for PMP and FAD. The LOD values obtained were comparable to those of other B 6 (20,25,27,29 ) and B 2 (39 ) assays.…”

Section: Performance Of the Methodssupporting

confidence: 79%

“…This often gives relatively long analysis times of ϳ30 min or longer (18,19,23,(25)(26)(27). In studies involving vitamin B 6 in plasma, usually only PLP was determined (20, 30 -34 ), but in some cases (5,10,29,35,36 ), several B 6 vitamers were measured.…”

mentioning

confidence: 99%

Multianalyte Quantification of Vitamin B6 and B2 Species in the Nanomolar Range in Human Plasma by Liquid Chromatography–Tandem Mass Spectrometry

Midttun¹,

Hustad²,

Solheim³

et al. 2005

Clinical Chemistry

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“…Plasma PLP was determined by the HPLC method ( 15 ). Urinary 4-PIC was determined by the HPLC method ( 16 ).…”

Section: Methodsmentioning

confidence: 99%

Effect of Fasting on the Urinary Excretion of Water-Soluble Vitamins in Humans and Rats

Fukuwatari

Yoshida

Takahashi

et al. 2010

J Nutr Sci Vitaminol

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Summary Recent studies showed that the urinary excretion of the water-soluble vitamins can be useful as a nutritional index. To determine how fasting affects urinary excretion of water-soluble vitamins, a human study and an animal experiment were conducted. In the human study, the 24-h urinary excretion of water-soluble vitamins in 12 healthy Japanese adults fasting for a day was measured. One-day fasting drastically decreased urinary thiamin content to 30%, and increased urinary riboflavin content by 3-fold. Other water-soluble vitamin contents did not show significant change by fasting. To further investigate the alterations of water-soluble vitamin status by starvation, rats were starved for 3 d, and water-soluble vitamin contents in the liver, blood and urine were measured during starvation. Urinary excretion of thiamin, riboflavin, vitamin B 6 metabolite 4-pyridoxic acid, nicotinamide metabolites and folate decreased during starvation, but that of vitamin B 12 , pantothenic acid and biotin did not. As for blood vitamin levels, only blood vitamin B 1 , plasma PLP and plasma folate levels decreased with starvation. All water-soluble vitamin contents in the liver decreased during starvation, whereas vitamin concentrations in the liver did not decrease. Starvation decreased only concentrations of vitamin B 12 and folate in the skeletal muscle. These results suggest that water-soluble vitamins were released from the liver, and supplied to the peripheral tissues to maintain vitamin nutrition. Our human study also suggested that the effect of fasting should be taken into consideration for subjects showing low urinary thiamin and high urinary riboflavin. Key Words human, rats, fasting, urine, biomarker A biological assay technique to assess water-soluble vitamins in healthy human subjects was reported by Melnick et al . in 1945 ( 1 ), and this technique became popular in the 1960 s and 1970 s. Urinary excretion of thiamin, riboflavin and niacin metabolites has been used for setting Dietary Reference Intakes (DRIs) of vitamin B 1 , vitamin B 2 and niacin in the USA and Japan ( 2 , 3 ). Recent validation studies have developed the urinary compounds as nutritional markers to estimate nutrient intakes. We have recently reported that each of the water-soluble vitamins or its metabolite levels in the 24-h urine are strongly correlated with its intake when young women consume the standard Japanese diet with several amounts of water-soluble vitamin ( 4 ). Thirtyday mean thiamin levels in 24-h urine are also highly correlated with mean intake of vitamin B 1 ( 5 ). These findings show that urinary excretion of water-soluble vitamins reflects their intakes when subjects constantly take certain amounts of water-soluble vitamins. It is well known that pharmacological doses of water-soluble vitamins acutely increase their excretion to urine, and that a chronic water-soluble vitamin restricted diet reduces its levels in urine and blood ( 6 ). Effects of acute deprivation of water-soluble vitamins on their urinary excretion have a...

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“…Vitamin B6: Plasma PLP was determined by the HPLC method (10). For analysis of 4-PIC, a metabolite of pyridoxal, 1 mL of 1 mol/L HCl was added to 9 mL urine.…”

Section: Determination Of Vitamins and Their Metabolites In Blood Andmentioning

confidence: 99%

Intra- and Inter-Individual Variations of Blood and Urinary Water-Soluble Vitamins in Japanese Young Adults Consuming a Semi-Purified Diet for 7 Days

Shibata

Fukuwatari

Watanabe

et al. 2009

J Nutr Sci Vitaminol

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SummaryWe have previously reported the levels of water-soluble vitamins in the blood and urine of Japanese young adults. In the present paper, to assess the variations in these water-soluble vitamin markers during the above experiment, we comprehensively determined the intra-and inter-individual variations of blood and urinary water-soluble vitamins to exactly the same amount of water-soluble vitamin intakes in the same experiment. The blood samples before breakfast and the 24-h urine samples were periodically collected from Japanese college male ( n ϭ 10) and female ( n ϭ 10) students consuming a semi-purified diet with water-soluble vitamins based on Japanese Dietary Reference Intakes for 7 d, and the intra-and inter-individual variations of blood and urinary water-soluble vitamins or their metabolites in blood and urine samples after adaptation were calculated. Although urinary excretion of vitamin B 12 and vitamin C showed high intra-individual variations in both males and females, other urinary vitamins and all blood vitamins showed less than 20% of within-subject coefficients of variance in either male or female. Those showing more than 20% of between-subject coefficients of variances in both male and female were blood vitamin B 6 , vitamin B 12 and folate levels, and urinary vitamin B 1 , vitamin B 2 , vitamin B 12 , nicotinamide metabolites, pantothenic acid, biotin and vitamin C. These results showed that oral administration of constant of water-soluble vitamins generally decreased intra-individual variation, while individual differences in urinary vitamin excretion were observed. Key Words water-soluble vitamins, blood, urine, human study A decrease of the vitamin contents in the body causes a vitamin deficiency, and vitamin levels in blood and urine are low in that state. The concentration of nutrients is well controlled in healthy people, and their blood and urinary water-soluble vitamin levels are kept constant. Therefore, water-soluble vitamin contents in blood and urine are used to assess their status, and these indicators have also been used for estimating dietary reference intakes (DRIs) in the USA and Japan ( 1 , 2 ). The use of valid nutritional markers for watersoluble vitamins is helpful to evaluate one's nutritional status for the vitamins, and further assessment of water-soluble vitamin levels in blood and urine is important to use as more established nutritional markers. To determine water-soluble vitamin levels in the blood and urine of Japanese subjects, we have previously reported those values obtained from the last day of experiments in Japanese young adults consuming a semi-purified diet based on the Japanese Recommended Dietary Allowance for 7 d ( 3 ). Although the subjects took exactly the same amount of vitamins for consecutive 7 d and followed the same schedule through the experiment, their water-soluble vitamin contents in blood and urine were different by individual ( 3 ). It is well known that these biomarkers show some individual differences; however, how individuals respond ...

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Clinical analysis of vitamin B6: Determination of pyridoxal 5′-phosphate and 4-pyridoxic acid in human serum by reversed-phase high-performance liquid chromatography with chlorite postcolumn derivatization

Cited by 62 publications

References 38 publications

Multianalyte Quantification of Vitamin B6 and B2 Species in the Nanomolar Range in Human Plasma by Liquid Chromatography–Tandem Mass Spectrometry

Multianalyte Quantification of Vitamin B6 and B2 Species in the Nanomolar Range in Human Plasma by Liquid Chromatography–Tandem Mass Spectrometry

Effect of Fasting on the Urinary Excretion of Water-Soluble Vitamins in Humans and Rats

Intra- and Inter-Individual Variations of Blood and Urinary Water-Soluble Vitamins in Japanese Young Adults Consuming a Semi-Purified Diet for 7 Days

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