Vitamin D Supplementation Reduces Renin-Angiotensin System Activity in Obesity

This study has been completed.
Information provided by (Responsible Party):
Jonathan S. Williams, MD, MMSc, Brigham and Women's Hospital Identifier:
First received: February 11, 2010
Last updated: July 5, 2012
Last verified: July 2012

Hypothesis: Vitamin D supplementation lower renin-angiotensin system activity in obesity.

Specific Aim: To investigate whether Vitamin D supplementation in obesity improves the vascular sensitivity to angiotensin II.

Condition Intervention
Vitamin D Deficiency
Dietary Supplement: Vitamin D (cholecalciferol)

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Open Label
Official Title: Vitamin D Deficiency Augments Renin-Angiotensin System Activity in Obesity

Resource links provided by NLM:

Further study details as provided by Brigham and Women's Hospital:

Primary Outcome Measures:
  • The blood pressure response to angiotensin II [ Time Frame: 1.5 years ]

Secondary Outcome Measures:
  • The renal blood flow response to angiotensin II [ Time Frame: 1.5 years ]

Enrollment: 19
Study Start Date: February 2010
Study Completion Date: September 2011
Primary Completion Date: September 2011 (Final data collection date for primary outcome measure)
Intervention Details:
    Dietary Supplement: Vitamin D (cholecalciferol)
    cholecalciferol 15,000 IU daily for 30 days
Detailed Description:

Vitamin D deficiency and obesity are international epidemics that have both been associated with increased activity of the renin-angiotensin system (RAS). Because increased RAS activity is associated with cardiovascular disease, interventions to lower RAS will have favorable public health impacts.

This study aims to evaluate whether the supplementation of Vitamin D in obese subjects will lower local tissue RAS activity. RAS activity will be evaluated by cross-sectional measurement of RAS components and by quantifying the vascular response to an infusion of angiotensin II. Subjects will be studied while Vitamin D deficient, and will return for repeat study following Vitamin D supplementation, for comparison.


Ages Eligible for Study:   18 Years to 64 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • age < 65,
  • Cr < 1.6,
  • 25-hydroxyvitamin D < 25 ng/mL,
  • BMI > 30 kg/m2,
  • stage I hypertension.

Exclusion Criteria:

  • diabetes,
  • coronary heart disease,
  • heart failure,
  • renal failure,
  • liver failure,
  • hyperparathyroidism,
  • granulomatous disease.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01068418

United States, Massachusetts
Brigham and Women's Hospital
Boston, Massachusetts, United States, 02115
Sponsors and Collaborators
Brigham and Women's Hospital
Principal Investigator: Jonathan S Williams, MD, MMSc Brigham and Women's Hospital
Study Director: Anand Vaidya, MD Brigham and Women's Hospital
  More Information

Responsible Party: Jonathan S. Williams, MD, MMSc, Assistant Professor of Medicine, Brigham and Women's Hospital Identifier: NCT01068418     History of Changes
Other Study ID Numbers: 2009p002062 
Study First Received: February 11, 2010
Last Updated: July 5, 2012

Keywords provided by Brigham and Women's Hospital:
Renin Angiotensin System
Vitamin D deficiency

Additional relevant MeSH terms:
Vitamin D Deficiency
Vascular Diseases
Cardiovascular Diseases
Nutrition Disorders
Body Weight
Signs and Symptoms
Deficiency Diseases
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents processed this record on January 19, 2017