Assessment of the Efficacy of Vitamin D Supplementation to Sustain Performance of Military-Relevant Laboratory Tasks Under Acutely Stressed Conditions: A Randomized, Double-Blind, Placebo-Controlled Study
Walter Reed Army Institute of Research (WRAIR)
Summary
The goal of this clinical trial is to find out if vitamin D supplements help healthy adults maintain their cognitive and simple physical task performance and emotional state during highly stressful situations. The main question it aims to answer is: \- Does vitamin D help maintain cognitive and physical task performance and emotional state during highly stressful situations? Researchers will compare vitamin D to placebo (a look-alike tablet that contains no active ingredients) to see if vitamin D better maintain cognitive and physical task performance and emotional state during highly stressful situations. Participants will: * Take vitamin D or placebo tablets daily for 8 weeks. * Perform cognitive and simple physical tasks and rate their emotional state under highly stressful situations. * Wear a stress belt that delivers mild electric shocks 1 - 5 times while participants are performing laboratory tasks. * Wear a wristwatch-shaped activity monitor for 9 weeks. * Visit the laboratory 5 times.
Eligibility
- Age range
- 18–40 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * Male and non-pregnant, non-lactating females 18 to 40 (inclusive) years of age. * Females of child-bearing potential must be using some form of birth control, if sexually active (e.g., oral contraceptive, condom, intrauterine device, etc.) * Score of 80% or greater on a "Volunteer Comprehension Assessment" test. A maximum of two attempts is permitted. * Blood 25 hydroxy vitamin D \[25(OH)D\] levels at the Screening visit of 30 nmol/L (12 ng/mL) (inclusive) - \< 75 nmol/L (30 ng/mL). Exclusion Criteria: * Contraindications due to vitamin D supplementation, including a h…