Effects of Vitamin B12 on the Body's Internal Clock

January 12, 2010 updated by: Brigham and Women's Hospital

Effect of Vitamin B12 on the Human Circadian Pacemaker

Circadian rhythms are 24-hour cycles that influence natural functions in the body such as heart rate, blood pressure, and body temperature. Circadian rhythms provide the body with an internal clock and affect sleep patterns. The purpose of this study is to determine the effects of vitamin B12 supplements on circadian rhythms and sleep-wake regulation.

Study Overview

Status

Completed

Conditions

Sleep Disorders, Circadian Rhythm

Intervention / Treatment

Drug: Vitamin B12

Detailed Description

Individuals with circadian rhythm sleep disorder suffer from recurrent patterns of disrupted sleep that can significantly affect their daily functioning. Evidence suggests that vitamin B12 supplements may have a beneficial effect on sleep patterns. However, research on the effects of vitamin B12 supplements on sleep is limited. This study will determine the effects of vitamin B12 supplements on circadian rhythms and sleep-wake regulation.

This study will last 47 days. Participants will undergo a 3-week medical and psychological screening prior to study entry. Eligible participants will be admitted to the General Clinical Research Center where they will live in a private study room for the duration of the study. The room will be a time-free environment with no windows, clocks, television, or radio. Participants will not be able to make or receive telephone calls, and their bedtimes, wake times, and mealtimes will be determined by study researchers. Participants will be randomly assigned to receive three capsules of either vitamin B12 or placebo daily. Blood and saliva collection will occur daily to determine core body temperature and hormone levels. Performance tests to determine participants' cognitive abilities will be administered at regular intervals throughout each day. Participants' sleep will be recorded every night with polysomnography, which will monitor brain and muscle activity and breathing patterns during sleep.

Study Type

Interventional

Enrollment (Actual)

Phase

Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

United States
- Massachusetts
  - Boston, Massachusetts, United States, 02115
    - Brigham and Women's Hospital, Harvard Medical School

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years to 26 years (Adult)

Accepts Healthy Volunteers

Genders Eligible for Study

All

Description

Inclusion Criteria:

Diagnosis of delayed sleep phase syndrome OR self-described as a "night owl"

Exclusion Criteria:

History of medical illness
History of psychiatric illness in participant or his or her family members
Current medication or vitamin use
Follow a vegan diet
Significant visual problem
Recent travel across time zones
History of rotating shiftwork

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Interventional Model: Parallel Assignment
Masking: Triple

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in circadian period Time Frame: first 2 weeks vs. final 2 weeks of period assessments	first 2 weeks vs. final 2 weeks of period assessments

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Brigham and Women's Hospital

Collaborators

National Center for Complementary and Integrative Health (NCCIH)

Investigators

Principal Investigator: Jeanne F. Duffy, PhD, Brigham and Women's Hospital, Harvard Medical School

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 2005

Primary Completion (Actual)

December 1, 2007

Study Completion (Actual)

January 1, 2008

Study Registration Dates

First Submitted

July 13, 2005

First Submitted That Met QC Criteria