Actively Recruiting
Evaluating Response to Vitamin D3 and K2 Supplementation in Healthcare Personnel
Led by Madigan Army Medical Center · Updated on 2025-09-30
96
Participants Needed
1
Research Sites
48 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
The main purpose of this research study is to learn about the effects of supplemental vitamin D3 and vitamin K2 on blood levels and the gut microbial community, called the gut microbiome. There are many influences on blood levels of vitamin D and K to include your dietary intake, lifestyle behaviors (physical activity, sleep), genetic alterations in metabolism of these vitamins, and the gut microbial abundance and diversity. You will be asked to take one capsule containing vitamin D3 (125 mcg), vitamin K2 (180 mcg), a combination of vitamins D3 and K2 (same doses as previous), or a placebo powder for 90 days. You will also be asked to complete questionnaires, undergo body composition and blood pressure measurements, provide blood samples and a stool swab, all on 2 occasions about 3 - 4 months apart. By conducting this study, we aim to identify the frequency of common genetic alterations in vitamins D and K metabolism and establish the impact on the gut microbiome for the first time. Your participation in this study will last about 4 - 6 months and include up to 3 visits.
CONDITIONS
Official Title
Evaluating Response to Vitamin D3 and K2 Supplementation in Healthcare Personnel
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Able to read and understand English
- 25 OHD serum level equal to or less than 30 ng/mL
- Willing to discontinue vitamin D3 and/or K2 supplements for 4.5 months
- Military beneficiary (Active Duty, Retired, Dependent)
- Expected to remain employed at workplace for 6 months
You will not qualify if you...
- Diagnosed medical condition preventing nutrient absorption (e.g., Inflammatory Bowel Disease, Celiac Disease, post-Roux-en-Y/Gastric sleeve surgery)
- Pregnant or breastfeeding
- Current antibiotic use or use within past 3 months
- Current anticoagulant use or use within past 3 months
- Current weight loss or fat malabsorption medication use (e.g., Glucagon-Like Peptide 1 agonists, Orlistat)
- Allergies or sensitivities to methylcellulose, vitamin D (D3, D2), or vitamin K (K2, Menaquinone-4, Menaquinone-7)
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Trial Site Locations
Total: 1 location
1
Madigan Army Medical Center
Tacoma, Washington, United States, 98431
Actively Recruiting
Research Team
M
Mary S McCarthy, PhD
CONTACT
H
Hyojin C Yi, BSN
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
4
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here