Vitamin B6 Supplementation and Mood States in College Women Taking Oral Contraceptives

This study is a 12-week, randomized, double-blinded crossover trial. After eligibility is confirmed through prescreening and onsite screening assessments (screening visit; ~30 minutes), participants will sign the consent form and enter the trial. Participants are stratified by age, BMI, and length of oral contraceptive use and randomized by a coin flip into the experimental group (B6 supplement) or control group (low does vinegar pill). Participants will visit the test site in the fasted state (no food or drink with the exception of water for 10 hours) on 4 occasions (pre and post weeks 1-4 and pre and post weeks 9-12) These visits are approximately 30 minutes long. At the start of the trial, participants are instructed to take the provided pills once daily for four weeks. For weeks 5-8, participants will not take any pills (the washout period). Daily pill consumption will resume during weeks 9-12 (the crossover treatment). Participants are their own control in this crossover trial.

All participants are instructed to maintain their normal exercise and eating patterns consistently throughout the duration of the 12-week study. Additionally, participants are instructed not to start any new medications or nutritional/herbal supplements. To promote compliance, participants will have a calendar to check off each day that the pills are consumed during the study.

Anthropometric data are collected and fasting blood draws are performed at weeks 0, 4, 9 and 12. Fasting blood samples will be tested for B6 and associated metabolites. Additionally, mood assessments, including the Profile of Mood States and the Beck Depression Inventory will be administered at weeks 0, 4, 9 and 12.

Inclusion criteria

• Female who has taken a combined oral contraceptive (estrogen with progestin) consistently for at least one year
• Healthy by self-report; no active disease state, depressive state, or prescription medication use (exception: OC)
• 18-25 years of age
• Nonsmoking
• Not pregnant or lactating if female
• Not a regular user of supplements aside from multivitamin/mineral supplement
• Dietary B6 at or below the RDA (1.3 mg/day)
• Not vegetarian/vegan
• Not a competitive athlete

Exclusion criteria

• Unwilling to take a vitamin supplement or placebo daily as prescribed during the 12 week study
• Unable to meet with investigators and provide a fasting blood sample on 4 occasions over a 12 week period