Evaluating Response to Vitamin D3 and K2 Supplementation in Healthcare Personnel

Conditions

• Hypovitaminosis
• Hypovitaminosis D

Eligibility Criteria

Sex

ALL

Age

18 Years - 69 Years

Healthy Volunteers

Accepted

Interventions

• Vitamin Arm 1 — DIETARY_SUPPLEMENT
  Subject receives dietary supplement for 90 days
• Vitamin Arm 2 — DIETARY_SUPPLEMENT
  Subject receives dietary supplement for 90 days
• Vitamin Arm 3 — DIETARY_SUPPLEMENT
  Subject receives dietary supplement for 90 days
• Placebo — OTHER
  Subject receives placebo for 90 days

Study Details

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.

Key Dates

Start date

Mar 27, 2025

Status verified

Sep 2025

Primary completion

Mar 31, 2026

Completion

Mar 31, 2026

Study Design

Enrollment

96 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Active Comparator: Vitamin Arm 1
  Vitamin D3 125 mcg taken orally once daily for 90 days
• Active Comparator: Vitamin Arm 2
  Vitamin K2 180 mcg taken orally once daily for 90 days
• Active Comparator: Vitamin Arm 3
  Vitamin D3 125 mcg combined with vitamin K2 180 mcg taken orally once daily for 90 days
• Placebo Comparator: Placebo Arm
  Inert capsule taken orally once daily for 90 days

Primary Outcome Measure

Gut microbiome composition [ Time Frame: 90 days ]

Central Contacts

• Mary S McCarthy, PhD
  253-968-3695
  [email protected]
• Hyojin C Yi, BSN
  253-968-2898
  [email protected]

Locations (1)

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