Vitamin B6 Effects for Women Taking Birth Control Pills
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|ClinicalTrials.gov Identifier: NCT01128244|
Recruitment Status : Completed
First Posted : May 21, 2010
Results First Posted : December 17, 2014
Last Update Posted : February 7, 2017
|Condition or disease||Intervention/treatment||Phase|
|Vitamin B6 Deficiency||Dietary Supplement: Vitamin B6 Procedure: Infusion of labeled serine, methionine and leucine||Phase 2 Phase 3|
Potential subjects will undergo a prescreening visit to meet the inclusion criteria, have a history, physical exam and routine labs drawn. The labs will verify the nutritional eligibility of folate, vitamin B12 and vitamin B6. If the inclusion criteria is met then the following will take place.
The subjects will come to the University of Florida (UF) Clinical and Translational Science Institute (CTSI) Clinical Research Center (CRC) for a 9 hour infusion (with stable isotope labeled serine, methionine and leucine) twice during the research study. Once at the start of the study and again at day 29. Blood samples will be taken for metabolite analysis. The infusion of nonradioactive, stable isotope labeled amino acids allows determination of the rate of metabolic reactions in one-carbon metabolism. The results from all subjects' blood analyses will provide us with information about rates of several parts of metabolism and vitamin B6 status.
During the 2-days prior to the infusion a controlled diet will be required. The subjects will be fed at the CTSI CRC. Dietary calculations and formulations will be conducted by using Minnesota Nutrition Data Systems software. Subjects will come to the CRC twice per day where they will meet with staff, consume morning and evening meals, and will be provided a sack lunch and snacks (including weekends). Protein intake will be kept constant.
After the first infusion, all subjects will consume their self-selected usual diets for 28 days along with a commercial B6 supplement providing 10 mg/day. Weekly measurement of blood will be used to verify compliance. All subjects will then consume a 2-day controlled diet at the UF CRC to normalize protein intake, followed by an infusion procedure identical to the first.
During the 4-week supplementation period, all subjects will come to the CRC weekly for weighing, blood samples, and consultation with staff. Careful screening, close monitoring and education of subjects, along with weekly monitoring of blood levels, all contribute to a high degree of compliance.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||13 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Official Title:||Vitamin B6 Effects on One-Carbon Metabolism|
|Study Start Date :||April 2010|
|Actual Primary Completion Date :||June 2014|
|Actual Study Completion Date :||June 2014|
Experimental: Vitamin B6 Effects in OC Users
All subjects will be given an infusion of labeled serine, methionine and leucine prior to vitamin B6 supplementation and after 28 days of treatment. In addition, they will receive a special diet 2 days prior to the infusion and will have weekly weight, blood, and visits to the clinic.
The results from analysis of vitamin B6 and these amino acids in blood will provide us with specific measurements of the rates of two aspects of metabolism (Primary Outcomes 1 and 2) and specific measurements of vitamin B6 nutritional status (Primary Outcomes 3 and 4).
Dietary Supplement: Vitamin B6
Subjects will receive vitamin B6 supplementation.
Procedure: Infusion of labeled serine, methionine and leucine
Subjects will be given an infusion of the stable isotope labeled amino acids, serine, methionine and leucine prior to vitamin B6 supplementation and after 28 days of B6 treatment. In addition, they will receive a special diet 2 days prior to the infusion and will have weekly weight, blood, and visits to the clinic.
- Total Remethylation of Homocysteine [ Time Frame: Blood samples will be taken prior to infusion and at 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7.5, and 9h. Infusions will be conducted at baseline and after 28 days ]Data from analysis of serine, methionine and leucine in the timed blood samples of all subjects will provide a measurement of the metabolic rate of total remethylation of homocysteine before and after vitamin B6 supplementation.
- Flux of Homocysteine Remethylation From Serine-derived Carbon [ Time Frame: Blood samples will be taken prior to infusion and at 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7.5, and 9h. Infusions will be conducted at baseline and after 28 days ]Data from analysis of serine, methionine and leucine in the timed blood samples of all subjects will provide a measurement of the metabolic rate of homocysteine remethylation from serine-derived carbon before and after vitamin B6 supplementation. These flux values may be slightly higher than flux of total homocysteine remethylation in Outcome Measure 1 because of the small contribution of methionine salvage to the flux measured in Outcome Measure 2.
- Fasting Plasma Pyridoxal Phosphate Concentration [ Time Frame: Fasting blood samples will be taken at baseline and after 28 days of vitamin B6 supplementation. ]For all subjects, the concentration of plasma pyridoxal phosphate in fasting blood samples taken before and after the supplementation period will provide a direct measure of vitamin B6 nutritional status.
- Fasting Plasma Cystathionine Concentration [ Time Frame: Fasting blood samples will be taken at baseline and after 28 days of vitamin B6 supplementation. ]For all subjects, the concentration of plasma cystathionine in fasting blood samples taken before and after the supplementation period will provide a functional measure of vitamin B6 nutritional status.
- Plasma 3-hydroxykynurenine Concentration [ Time Frame: April, 2010 - June, 2014 ]For all subjects, analysis of blood samples before and after vitamin B6 supplementation will allow evaluation of discriminating biomarkers using targeted metabolite profile analysis of one-carbon metabolism and tryptophan catabolism constituents. Also, we will conduct exploratory evaluation and potential identification of new biomarkers using metabolomics analysis on subjects before and after vitamin B6 supplementation.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01128244
|United States, Florida|
|University of Florida Clinical Research Center|
|Gainesville, Florida, United States, 32610|
|Principal Investigator:||Jesse Gregory, PhD||University of Florida|