Vitamin D Intervention and Associated Changes in the Gut Microbiome and Vitamin D Levels in Healthy Adults

Study Overview
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Brief Summary
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Although dietary vitamin D supplementation has been used in the clinical setting for decades, the effect of supplementary vitamin D consumption on the structure of the microbiome has not been studied in humans in fine scale or with concomitant adjustment for dietary intake. Understanding the interaction of vitamin D with the microbiome in humans could lead to important advancements in the understanding of how vitamin D together with diet impacts the microbiome composition, and ultimately, risk of EOCRC. This study has the potential to lay the ground work for an adjunctive therapy to manipulate the microbiome to reduce risk of EOCRC. This proposed study is designed to evaluate the effect of vitamin D supplementation on the normal structure of the microbiome and data will not be used to diagnose, prevent, cure or treat disease.

Official Title
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Association of Vitamin D Supplementation and Normal Dietary Intake of Vitamin D With Changes in the Gut Microbiome and Markers of Colorectal Cancer Risk

Conditions
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Colorectal Cancer

Intervention / Treatment
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* Dietary Supplement: Vitamin D intervention
* Dietary Supplement: Placebo intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult 18 years or older Exclusion Criteria: Women who are currently pregnant or breastfeeding Use of antibiotics within the last 2 weeks Use of supplementary vitamin D within the last month Self-reported, pre-existing history of inflammatory bowel disease, heart disease or diabetes Students under 18 Tanning/sun exposure > 60 min at a time in last 4 weeks No phenobarbital, carbamazepine, spironolactone chronic therapy; or steroid use within the last 2 weeks Severe allergy to ingredients found in supplements

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 79 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Double blind placebo controlled randomized intervention of vitamin supplementation
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo intervention<br>A gummie candy the same consistency and nutrient value as the vitamin D gummie without any vitamin D will be taken as four gummies at the largest meal for 12 weeks once per day | Dietary Supplement: Placebo intervention<br>* Organic gummie candies (no vitamin D), 4 gummies per day for 12 weeks<br>|
| Experimental: Vitamin D intervention<br>A vitamin D gummie the same consistency and nutrient value as the placebo gummie will be taken as four gummies at the largest meal for 12 weeks once per day providing 4000 IUs per day or 1000 IUs per gummie | Dietary Supplement: Vitamin D intervention<br>* Nordic Naturals vitamin D gummies (1000 IUs/gummie), 4 gummies per day for 12 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microbiome alterations | Change in the microbiome structure and function | 12 weeks |