This subproject is one of many research subprojects utilizing theresources provided by a Center grant funded by NIH/NCRR. The subproject andinvestigator (PI) may have received primary funding from another NIH source,and thus could be represented in other CRISP entries. The institution listed isfor the Center, which is not necessarily the institution for the investigator.Marginal vitamin B6 deficiency, which occurs commonly worldwide, leads to a cellular deficiency of the coenzyme pyridoxal phosphate (PLP). PLP is a coenzyme in several phases of one carbon (1C) metabolism, which is the array of reactions in which one carbon units are acquired and used in reactions including nucleotide synthesis, regeneration of methionine (Met) from homocysteine (Hcy), and methylation of many biological compounds. 1C metabolism is linked to the transsulfuration pathway in which Hcy undergoes PLP-dependent catabolism leading to cysteine, whose availability governs the formation of the antioxidant glutathione. Nutritional or genetic conditions that impair 1C metabolism are associated with elevation in plasma Hcy concentration and increased risk of vascular disease. It is believed that the metabolic effects of vitamin B6 deficiency will be most pronounced following protein intake when the vitamin B6-dependent pathways of amino acid metabolism experience the greatest substrate load. The human subjects protocols of this study consist of two distinct phases intended to extend our understanding of basic human 1C metabolism and the effects of marginal vitamin B6 deficiency under postprandial conditions. Phase 1 will investigate the effects of vitamin B6 nutrition on the PLP-dependent generation of 1C units by the glycine cleavage system and on the synthesis of glutathione. Phase 2 will investigate the dependence of methionine metabolism on vitamin B6 nutritional status, with particular emphasis on the recycling of Hcy to Met. Each phase of this study will involve 14 healthy, nutritionally adequate, young adults (7 male, 7 female) who will undergo metabolite profiling and kinetic analysis using intravenously infused stable isotopic tracers performed both before and after a ~4-week period of dietary vitamin B6 restriction. Subjects will be assigned to either Phase 1 or Phase 2, which will be identical in design except for the tracers and analytical methods used. We hypothesize that vitamin B6 deficiency will yield reduction in postprandial rates of homocysteine remethylation, generation of 1C units from glycine, and synthesis of glutathione. The results of this study will aid in assessing the consequences of nutritional and genetic variables affecting human metabolism and will further our understanding of the relationships between vitamin B6 nutrition and disease.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
General Clinical Research Centers Program (M01)
Project #
Application #
Study Section
National Center for Research Resources Initial Review Group (RIRG)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Florida
Internal Medicine/Medicine
Schools of Medicine
United States
Zip Code
Mangal, Naveen; James, Margaret O; Stacpoole, Peter W et al. (2018) Model Informed Dose Optimization of Dichloroacetate for the Treatment of Congenital Lactic Acidosis in Children. J Clin Pharmacol 58:212-220
Boissoneault, Jeff; Letzen, Janelle; Lai, Song et al. (2016) Abnormal resting state functional connectivity in patients with chronic fatigue syndrome: an arterial spin-labeling fMRI study. Magn Reson Imaging 34:603-8
Shumyak, Stepan; Yang, Li-Jun; Han, Shuhong et al. (2016) ""Lupoid hepatitis"" in SLE patients and mice with experimental lupus. Clin Immunol 172:65-71
Hendeles, Leslie; Khan, Yasmeen R; Shuster, Jonathan J et al. (2015) Omalizumab therapy for asthma patients with poor adherence to inhaled corticosteroid therapy. Ann Allergy Asthma Immunol 114:58-62.e2
Price, Catherine C; Levy, Shellie-Anne; Tanner, Jared et al. (2015) Orthopedic Surgery and Post-Operative Cognitive Decline in Idiopathic Parkinson's Disease: Considerations from a Pilot Study. J Parkinsons Dis 5:893-905
Krueger, Charlene A; Cave, Emily C; Garvan, Cynthia (2015) Fetal response to live and recorded maternal speech. Biol Res Nurs 17:112-20
Jones, Jacob D; Marsiske, Michael; Okun, Michael S et al. (2015) Latent growth-curve analysis reveals that worsening Parkinson's disease quality of life is driven by depression. Neuropsychology 29:603-9
Morishita, Takashi; Foote, Kelly D; Archer, Derek B et al. (2015) Smile without euphoria induced by deep brain stimulation: a case report. Neurocase 21:674-8
Del-Aguila, J L; Cooper-DeHoff, R M; Chapman, A B et al. (2015) Transethnic meta-analysis suggests genetic variation in the HEME pathway influences potassium response in patients treated with hydrochlorothiazide. Pharmacogenomics J 15:153-7
Chapman, Arlene B; Cotsonis, George; Parekh, Vishal et al. (2014) Night blood pressure responses to atenolol and hydrochlorothiazide in black and white patients with essential hypertension. Am J Hypertens 27:546-54

Showing the most recent 10 out of 266 publications