The Effects of Vitamin D on Glycemic Control and Proinflammatory Markers in Adolescents With T1DM

Study Overview
=================
Brief Summary
-----------------
The investigators are conducting a prospective cross-over study to evaluate the effects of vitamin D supplementation on diabetes control and the pro-inflammatory markers involved in microvascular complications in adolescents with Type 1 Diabetes. The investigators expect to see a significant improvement in glycemic control and a reduction of serum pro-inflammatory markers in adolescents with Type 1 Diabetes and vitamin D deficiency or insufficiency, who are treated with vitamin D.

Official Title
-----------------
The Effects of Vitamin D Supplementation on Glycemic Control and Proinflammatory Markers Involved in Microvascular Complications in Adolescents With Type 1 Diabetes.

Conditions
-----------------
Type 1 Diabetes, Vitamin D Deficiency/Insufficiency

Intervention / Treatment
-----------------
* Dietary Supplement: Vitamin D


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Between 13 to 21 years of age, with at least Tanner stage 4 sexual maturity for males or post-menarchal females, and T1DM for at least 1 year. To ensure that inclusion criteria for sexual maturity are met, a physical exam for research purposes will be performed. HbA1c between 7 to 9% Adequate renal function (serum creatinine < 1.5 mg/dL in males and < 1.2 mg/dL in females) and adequate liver function (AST and ALT < 2.5 times the upper limit of normal) Vitamin D insufficiency or deficiency (25-OH vit D level < 30ng/mL) which will be determined on initial screening labs after consenting subjects. Exclusion Criteria: Less than 13 or greater than 21 years of age Less than Tanner stage 4 sexual maturity for males or pre-menarche HbA1c less than 7% or greater than 9% T1DM for less than 1 year Vitamin D sufficient (25-OH vit D level > 30 ng/mL) Currently taking any medication that can interfere with vitamin D synthesis or metabolism, including but not limited to Orlistat, Phenobarbital, Dilantin, Anti-tuberculosis drugs Currently taking any medication other than insulin that alters blood glucose levels, including but not limited to systemic glucocorticoids Inadequate renal function (serum creatinine > 1.5mg/dL in males and > 1.2mg/dL in females) or inadequate liver function (AST and ALT > 2.5 times the upper limit of normal) Evidence of malabsorption or short gut.

Ages Eligible for Study
-----------------
Minimum Age: 13 Years
Maximum Age: 21 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Immediate treatment group<br>This group will receive vitamin D supplementation for the first 6 months, then will be monitored off vitamin D for the next 6 months. | Dietary Supplement: Vitamin D<br> <br> |
| Other: Delayed treatment group<br>This group will be monitored for the first 6 months, and then will be given vitamin D for the next 6 months. | Dietary Supplement: Vitamin D<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hemoglobin A1c | The primary endpoint in this study will be the difference in change in Hemoglobin A1c between the treatment and non-treatment periods (6 months) | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pro-inflammatory markers | Change in pro-inflammatory markers (CRP, IL-6, TNF-α) between treatment and non-treatment periods | 6 months | 
| Vitamin D level and proinflammatory markers | Correlation between change in vitamin D levels and circulating pro-inflammatory markers, including CRP, IL-6, and TNF-α | 6 months | 
| Vitamin D levels on insulin requirements | Correlation between the change of vitamin D levels on insulin requirements | 6 months | 
| Vitamin D level and HbA1c | Correlation between the change in vitamin D level in the blood and change in HbA1c | 6 months | 
| Baseline differences between vitamin D deficient & sufficient subjects | Comparison of baseline differences between vitamin D deficient/insufficient subjects and vitamin D sufficient subjects (including pro-inflammatory markers, HbA1c and total daily insulin requirements | Baseline | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Diabetes, Vitamin D, Proinflammatory markers