Vitamin D Supplementation in Overweight/Obese African American Adults and Youth (D-SUNNY)

Study Overview
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Brief Summary
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Primary Specific Aim 1: To compare the dose-responsive effects of vitamin D3 supplementations on 25(OH) D, parathyroid hormone (PTH), and serum/urine calcium. Primary Specific Aim 2: To compare the dose-responsive effects of vitamin D3 supplementations on non-invasive vascular measures including pulse wave velocity (PWV), flow-mediated dilation (FMD), carotid arterial compliance (CAC), carotid Intima-Media Thickness (cIMT), and 24-hours Ambulatory Blood Pressure (ABP) monitoring as well as casual BP.

Official Title
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Vitamin D Supplementation in Overweight/Obese African American Adults and Youth (D-SUNNY)

Conditions
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Vitamin D Deficiency

Intervention / Treatment
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* Dietary Supplement: Cholecalciferol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: African-Americans (blacks) Age 13-45 Overweight/obese (BMI ≥ 85th percentile for their age and gender for age 13-17 and BMI ≥ 25 kg/m2 for age 18-45) Relatively healthy (no medical history of any heart, lung, endocrine or malignant disorder) Non pregnant Not on any medication or vitamin supplements that can influence the study outcomes Serum 25 hydroxy Vitamin D (25[OH] D) levels ≤ 20 ng/ml (50 nmol/L) at the time of screening Exclusion Criteria: Not meeting any one or more of the above criteria Females who become pregnant/test positive on urine pregnancy test during the screening or any of the testing visits Anyone who is taking any multivitamin supplements that contains vitamin D

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 45 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: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Placebo<br>Placebo group | |
| Experimental: Supplementation arm 1<br>cholecalciferol 18000 U/month for 4 months | Dietary Supplement: Cholecalciferol<br>* The participants will be randomized into one of the four groups. Group 0 will be placebo group, group 1 will receive monthly supervised dose of 18,000 IU (equivalent to 600 IU/day), group 2 will receive monthly supervised dose of 60,000 IU(equivalent to 2000 IU/day), and group 3 will receive 120,000 IU (equivalent to 4000 IU/day) vitamin D3 supplementation for 4 months (16 weeks).<br>|
| Experimental: supplementation arm 2<br>cholecalciferol 60000 U/month for 4 months | Dietary Supplement: Cholecalciferol<br>* The participants will be randomized into one of the four groups. Group 0 will be placebo group, group 1 will receive monthly supervised dose of 18,000 IU (equivalent to 600 IU/day), group 2 will receive monthly supervised dose of 60,000 IU(equivalent to 2000 IU/day), and group 3 will receive 120,000 IU (equivalent to 4000 IU/day) vitamin D3 supplementation for 4 months (16 weeks).<br>|
| Experimental: Supplementation arm 3<br>cholecalciferol 120000 U/month for 4 months | Dietary Supplement: Cholecalciferol<br>* The participants will be randomized into one of the four groups. Group 0 will be placebo group, group 1 will receive monthly supervised dose of 18,000 IU (equivalent to 600 IU/day), group 2 will receive monthly supervised dose of 60,000 IU(equivalent to 2000 IU/day), and group 3 will receive 120,000 IU (equivalent to 4000 IU/day) vitamin D3 supplementation for 4 months (16 weeks).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiovascular phenotypes | Will be using non-invasive vascular measures including pulse wave velocity (PWV), flow-mediated dilation (FMD), carotid arterial compliance (CAC), carotid Intima-Media Thickness (cIMT), and 24-hours Ambulatory Blood Pressure (ABP) monitoring. | 16 weeks | 
| Primary outcome 1 dose-responsive effects of vitamin D3 supplementations | To compare the dose-responsive effects of vitamin D3 supplementations on 25(OH) D, parathyroid hormone (PTH), and serum/urine calcium. | 16 weeks | 
| Primary Outcome 2 dose-responsive effects of vitamin D3 supplementations | To compare the dose-responsive effects of vitamin D3 supplementations on non-invasive vascular measures including pulse wave velocity (PWV), flow-mediated dilation (FMD), carotid arterial compliance (CAC), carotid Intima-Media Thickness (cIMT), and 24-hours Ambulatory Blood Pressure (ABP) monitoring as well as casual BP. | 16 weeks |