Methionine Metabolite Excretion as Affected by a Vitamin B-6 Deficiency
The effect of a vitamin B-6 deficiency on the metabolism of methionine was investigated in three different studies conducted at the University of Wisconsin. In the first study, 49 days in length, six young men were subjects (1), and in the second study, 35 days in length, five young women participated (2). The purpose of these two studies was to determine the effect of a vitamin B-6 deficiency on the urinary excretion of homocystine, cystathionine, cysteine sulfinic acid and taurine, all metabolites of methionine whose formation and/or degradation are dependent upon the presence of vitamin B-6. The third study, 60 days in length, dealt with the effect of a vitamin B-6 deficiency on the metabolism of methionine by 14 oral contraceptive users and 10 nonusers as determined by the urinary excretion of the same five metabolites mentioned earlier (3). Since there was no significant difference between the oral contraceptive users and the nonusers in the excretion of any of the compounds, the two groups were combined for the purpose of this discussion.
KeywordsProtein Intake Protein Diet Kynurenic Acid Cysteic Acid Oral Contraceptive User
Unable to display preview. Download preview PDF.
- 1.Park, Y. K. Linkswiler, H. (1970) Effect of vitamin B-6 depletion in adult man on the excretion of cystathionine and other methionine metabolites. J. Nutr. 100, 110–116.Google Scholar
- 2.Shin, H. K. Linkswiler, H. M. (1974) Tryptophan and methionine metabolism of adult females as affected by vitamin B-6 deficiency. J. Nutr. 104, 1348–1355.Google Scholar
- 3.Leklem, J. E., Linkswiler, H. M., Brown, R. R., Rose, D. P. Anand, C. R. (1977) Metabolism of methionine in oral contraceptive users and control women receiving controlled intakes of vitamin B-6. Am. J. Clin. Nutr. 30, 1122–1127.Google Scholar
- 4.Miller, L. T. Linkswiler, H. ( 1967 ] Effect of protein intake on the development of abnormal tryptophan metabolism by men during vitamin B-6 depletion. J. Nutr. 93, 53–59.Google Scholar
- 5.Sturman, J. A. (1978) Vitamin B-6 and the metabolism of sulfur amino acids. In: Human Vitamin B-6 Requirements, pp. 37–60. Nat. Acad. Sci., Washington, DC.Google Scholar