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Vitamin B6 Effects for Women Taking Birth Control Pills

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2014 by University of Florida
Sponsor:
Information provided by (Responsible Party):
University of Florida
ClinicalTrials.gov Identifier:
NCT01128244
First received: May 20, 2010
Last updated: May 19, 2014
Last verified: May 2014

May 20, 2010
May 19, 2014
April 2010
February 2015   (final data collection date for primary outcome measure)
  • Change in flux of 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 ] [ Designated as safety issue: No ]
    Outcome measurements include: (a) concentrations of metabolites associated with vitamin B6 metabolism and function, (b) the kinetics (rates) of metabolic reactions pertaining to one-carbon metabolism, and (c) the changes of the above variables following vitamin B6 supplementation.
  • Change in 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 ] [ Designated as safety issue: No ]
    Outcome measurements include: (a) concentrations of metabolites associated with vitamin B6 metabolism and function, (b) the kinetics (rates) of metabolic reactions pertaining to one-carbon metabolism, and (c) the changes of the above variables following vitamin B6 supplementation.
  • Change in fasting plasma pyridoxal phosphate concentration [ 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 ] [ Designated as safety issue: No ]
    Outcome measurements include: (a) concentrations of metabolites associated with vitamin B6 metabolism and function, (b) the kinetics (rates) of metabolic reactions pertaining to one-carbon metabolism, and (c) the changes of the above variables following vitamin B6 supplementation.
  • Change in fasting cystathionine concentration [ 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 ] [ Designated as safety issue: No ]
    Outcome measurements include: (a) concentrations of metabolites associated with vitamin B6 metabolism and function, (b) the kinetics (rates) of metabolic reactions pertaining to one-carbon metabolism, and (c) the changes of the above variables following vitamin B6 supplementation.
To evaluate if women on oral contraceptives are B6 deficient [ Time Frame: 28 days ] [ Designated as safety issue: No ]
Vitamin B6 Effects on One-Carbon Metabolism To determine if women on oral contraceptives who are B^ deficient can have the deficiency resolved after 28 days on supplemental Vitamin B6
Complete list of historical versions of study NCT01128244 on ClinicalTrials.gov Archive Site
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Vitamin B6 Effects for Women Taking Birth Control Pills
Vitamin B6 Effects on One-Carbon Metabolism

Chronically inadequate B6 nutritional status is associated with aberrant one-carbon (1C) metabolism and health. Plasma PLP >30 nmol/L often has been considered to be the cutoff indicative of nutritional adequacy, with 20-30 nmol/L considered marginal deficiency; however, the current RDA value was based on a more conservative cutoff of 20 nmol/L plasma PLP. As shown by in the investigators preliminary data, biochemical perturbations occur when humans have marginal B6 deficiency consistent with plasma PLP of 20-30 nmol/L. A prospective study also showed that plasma PLP <23.3 nmol/L is associated with 1.8-times higher risk of recurrent venous thromboembolism than those with PLP >23.3 nmol/L. The mechanism by which low B6 intake is associated with risk of vascular disease is not known. Since B6-deficiency has little tendency to raise fasting plasma tHcy but yields an elevated tHcy response following a methionine load, low B6 nutriture may lead to repeated transient mild hyperhomocysteinemia following meal consumption. Several reports of associations between elevated plasma C-reactive protein (CRP) and low B6 status have raised the hypothesis that systemic inflammation is prone to occur during B6 deficiency or contributes to low B6 status. The investigators previously found that healthy humans in low B6 status caused by dietary restriction exhibited normal plasma CRP levels. The investigators also postulate that oxidative stress associated with low B6 status, coupled with impaired glutathione synthesis, contributes to such risk. These questions indicate the need for a more thorough understanding of the metabolic changes occurring in low B6 status from marginal B6 intake and from drug interactions such as in women using oral contraceptives.

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 CTSI Shands Clinical Research Unit (CRU) for a 9 hour infusion 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.

During the 2-days prior to the infusion a controlled diet will be required. The subjects will be fed at the CTSI Shands CRU. Dietary calculations and formulations will be conducted by using Minnesota Nutrition Data Systems software. Subjects will come to the CRU 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, 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. The 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, subjects will come to the CRU 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.

Interventional
Phase 2
Phase 3
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Vitamin B6 Deficiency
  • Dietary Supplement: Vitamin B6
    Subjects will receive vitamin B6 supplementation.
    Other Names:
    • pyridoxine HCl supplement
    • USP pyridoxine HCL
  • Procedure: Infusion of amino acids, serine, and methionine
    Subjects will be given an infusion of the amino acids, serine, and methionine 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.
Experimental: Vitamin B6 Effects in OC Users
Subjects will be given an infusion of the amino acids serine and methionine 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.
Interventions:
  • Dietary Supplement: Vitamin B6
  • Procedure: Infusion of amino acids, serine, and methionine
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruiting
15
June 2015
February 2015   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • healthy female subjects
  • normal screening labs
  • normal body weight
  • nonpregnant
  • Plasma PLP<30nmol/L

Exclusion Criteria:

  • history of gastrointestinal surgery
  • chronic disease
  • vitamin supplementation
  • high protein diet
  • progesterone
  • no smoking
  • chronic drug use
  • alcoholism
  • no vitamin supplementation
Female
20 Years to 40 Years
Yes
Contact: Candy Caputo (352) 273-9023 Candace.caputo@medicine.ufl.edu
Contact: Luisa Rios-Avila, MS 352-392-1991 ext 266 lrios1@ufl.edu
United States
 
NCT01128244
2RO1DKO72398-05
No
University of Florida
University of Florida
Not Provided
Principal Investigator: Jesse Gregory, PhD University of Florida
University of Florida
May 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP