An Eight Week Double Blinded Randomized, Placebo-controlled Trial to Assess the Effect of Two Doses of 100,000 IU Vitamin D3 by Mouth on Select Genetic Responses in Overweight, Hypertensive African-Americans With Hypovitaminosis D

DETAILED DESCRIPTION OF STUDY PROCEDURES. Three hundred thirty (330) overweight, pre-hypertensive/controlled hypertensive, African-American participants will be enrolled in a 8 week study to assess the effect of two administrations of Vitamin D3 on Vitamin D serum responsiveness as a function of clinical, biologic and genetic factors. The investigators anticipate that at least 300 participants will complete this study.

Written, signed and dated informed consent to participate in the study will be given by the participant or a legally acceptable representative, in accordance with the International Conference on Harmonization (ICH) Good Clinical Practice (GCP) Guideline E6 and applicable regulations, before completing any study-related activities/procedures. The original signed and dated consent will be kept in the subject's research file and a copy given to the subject. A copy will also be placed in their medical record.

BLOOD PRESSURE CONTROL. Controlled high blood pressure is entry criteria, but not an outcome. However, the investigators want to exclude potential participants who are likely to have poor BP control during the study. Therefore, although patients with pre-hypertension or hypertension are eligible to be entered into the study, the protocol only allows enrollment of participants with well-controlled hypertension as defined by SBP≥ 120 mmHg or DBP ≥ 80 mmHg if not on treatment, and SBP <160 mmHg or DBP < 100 mmHg regardless of whether on treatment or not. BP care will be managed by the participants' primary or other provider. All participants being actively treated for hypertension with pharmacotherapy will receive direction to adhere to their medication and to follow-up with their Primary Care Physician. Patients with poorly controlled diabetes as defined by hemoglobin A1c > 8.5% or advanced kidney disease as defined by eGFR < 45 ml/min are excluded. After the study is concluded, all participants will be encouraged and supported to address issues of diet and exercise that may reduce their risk for hypertension. If BP medications need to be adjusted, participants will be referred back to their Primary Care Physician.

VISIT 1 - SCREENING. The screening period will allow for the determination of appropriateness of each subject's inclusion in the study. Written informed consent from the subject or their legally authorized representative would have been obtained prior to any study-related procedures being performed. In addition to signing the general informed consent, subjects who agree to participate the sub-study with fat biopsy will sign a second informed consent.

The subject will be assigned a screening number and will be contacted regarding eligibility once all screening procedures have been performed and laboratory results received.