Maintenance Dosing of Vitamin D in Crohn's Disease

Study Overview
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Brief Summary
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Vitamin D repletion is important for bone health in patients with Crohn's disease. While repletion strategies in the general population yield similar results in those with Crohn's disease, maintenance strategies are variable. High quality evidence is lacking to determine the optimal strategy to maintain adequate levels of Vitamin D levels in patients with Crohn's disease.

Detailed Description
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The investigators seek to identify patients with Crohn's disease in clinical remission who have vitamin D levels <30 ng/ml. Subjects will undergo a 8 week lead in period and receive Vitamin D supplementation with 50,000 IU D2 weekly for 8 weeks.Participants with sufficient Vitamin D levels after 8 weeks (>30 ng/mL) will be enrolled into the study and randomized to one of three arms: (1) placebo (2) 1000 IU/day Vitamin D3 (3) 5,000 IU/day Vitamin D3 for 22 weeks. Based on clinical experience, doses higher than the recommended doses for bone health in the general population (600-800 IU/day Vitamin D3) are needed to achieve and maintain optimal levels of Vitamin D in people with Crohn's disease. The investigators aim to determine optimal maintenance dosing to sustain vitamin D sufficiency in people with Crohn's disease. The investigators also seek to determine demographic and disease related characteristics associated with inability to maintain sufficient levels.

Official Title
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A Randomized, Double Blind, Placebo Controlled Trial Evaluating Optimal Maintenance Strategies of Vitamin D Levels in Patients With Crohn's Disease in Remission

Conditions
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Crohns Disease, Vitamin D Deficiency

Intervention / Treatment
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* Dietary Supplement: 5000 IU D3
* Dietary Supplement: 1000 IU D3
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of Crohn's disease In clinical remission as determined by the Harvey Bradshaw Index (CD) ≤4 25(OH)D level <30 ng/ml within three months of study enrollment Prior 25(OH)D level <30 ng/ml currently on repletion therapy Provided written informed consent 18 years of age or older All maintenance therapies required to be on stable doses for 3 months. Exclusion Criteria: Unwilling to provide consent or lack capacity Clinical disease activity (Harvey Bradshaw index >4) Current pregnancy or attempting to conceive Hypercalcemia (must have calcium level within 6 months of enrollment) Known coexisting hyperparathyroidism BMI >30 kg/m² History of kidney stones Subjects <18 years of age - pediatric population with different recommended dosing than adults Non-english speakers Has an ileo-anal pouch or ileostomy C-reactive protein greater than 2x the upper limit of normal Lactose intolerant Short gut syndrome Renal insufficiency (CrCl <60 ml/min) Concomitant therapy with thiazide diuretics, barbiturates, digitalis or supplemental products containing vitamin D Vitamin D levels <30ng/ml at completion of lead in

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Prospective, randomized controlled trial
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br> | Dietary Supplement: Placebo<br>* lactose/sugar tablet<br>|
| Active Comparator: Vitamin D 1000 IU D3 daily<br> | Dietary Supplement: 1000 IU D3<br>* Daily<br>|
| Active Comparator: Vitamin D 5000 IU D3 daily<br> | Dietary Supplement: 5000 IU D3<br>* Daily<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vitamin D serum level Vitamin D sufficiency | Serum level greater than or equal to 30 ng/ml | 22 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to Vitamin D Insufficiency | Time (in weeks) from the measurement of sufficiency (at week 0) to Vitamin D insufficiency (defined as serum vitamin D level less than 30 ng/mL) | 22 weeks |