DAYLIGHT: Vitamin D Therapy in Individuals at High Risk of Hypertension

Inclusion Criteria: * Males or females 18 to 50 years of age * Systolic blood pressure of 120 to 159 mmHg and Diastolic blood pressure ≤99 mmHg * Vitamin D deficiency, defined as 25-hydroxyvitamin D \<25 ng/ml * No use of any anti-hypertensive medication in last 3 months or anticipated or planned use in next 6 months * No use of vitamin D supplementation in last 3 months, defined as vitamin D found in a multivitamin or supplement totaling \>400 IU per day or anticipated or planned use in next 6 months Exclusion Criteria: * Use of any anti-hypertensive medication in last 3 months or anticipated or planned use in next 6 months * Use of vitamin D supplementation in last 3 months, defined as vitamin D found in a multivitamin or supplement totaling \>400 IU per day or anticipated or planned use in next 6 months * Use of St. John's wart, rifampin, any treatment for HIV, orlistat, oral glucocorticoids, phenobarbital, phenytoin, mineral oil, or bile acid sequestrants in the last 3 months or anticipated or planned use in next 6 months * Female who is pregnant, nursing, or of childbearing potential and planning or anticipating pregnancy in next 6 months * History of diabetes mellitus (including Type 1, Type 2 and diet controlled) * Serum creatinine \>2.0 mg/dl or estimated Glomerular Filtration Rate (GFR) \<30 ml/min * Calcium \>10.0 mg/dl or phosphorus \>5 mg/dl * History of kidney stones * Body mass index \>38 kg/m2 * Known cardiovascular disease: defined as prior myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass or stroke * History of cirrhosis or severe liver disease (defined as history of GI bleeding from liver disease, jaundice or ascites) * Current heavy alcohol use: defined as drinking 5 or more drinks per occasion on 5 or more days in the past 30 days * History of ulcerative colitis, Crohn's disease, celiac disease, colostomy, pancreatic enzyme deficiency, short bowel syndrome, gastric bypass, cystic fibrosis, or dumping syndrome. * Allergy to coconut * Regular use or planned use of artificial tanning lights in next 6 months * Use of any investigational product or device in last 3 months or planned use in next 6 months * Any condition which could limit the ability to complete and comply with 6-month follow up * Unwillingness or inability to comply with study requirements * Inability to provide informed consent