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

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

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.

Inclusion Criteria:

1. African-Americans (blacks)
2. Age 13-45
3. Overweight/obese (BMI ≥ 85th percentile for their age and gender for age 13-17 and BMI ≥ 25 kg/m2 for age 18-45)
4. Relatively healthy (no medical history of any heart, lung, endocrine or malignant disorder)
5. Non pregnant
6. Not on any medication or vitamin supplements that can influence the study outcomes
7. Serum 25 hydroxy Vitamin D (25[OH] D) levels ≤ 20 ng/ml (50 nmol/L) at the time of screening

Exclusion Criteria:

1. Not meeting any one or more of the above criteria
2. Females who become pregnant/test positive on urine pregnancy test during the screening or any of the testing visits
3. Anyone who is taking any multivitamin supplements that contains vitamin D