The Impact of Vitamin D Supplementation in Hypertensive Vitamin D Deficient Patients.

The Relationship of Vitamin D and Irisin With Blood Pressure and Heart Rate Variability in Normotensive and Hypertensive Individuals: The Impact of Vitamin D Supplementation in Hypertensive Vitamin D Deficient Patients.

This study will assess the impact of Vitamin D supplementation on hypertensive patients with Vitamin D deficiency, it will also investigate the relationship between serum Vitamin D, irisin levels, blood pressure, and heart rate variability (HRV) in hypertensive and normotensive individuals.

It is hypothesized that a decrease in blood pressure and an increase in HRV will be noted in the hypertensive treatment group (subjects on supplemental vitamin D) in comparison to the hypertensive control group (placebo) upon vitamin D supplementation.

Study Overview

• Status: Completed
• Conditions: Hypertension; Vitamin D Deficiency
• Intervention / Treatment: Dietary supplement: Placebo Capsule(s); Dietary supplement: Vitamin D (Cholecalciferol )

Detailed Description

In a prospective study conducted on 160 participants, 80 hypertensive and 80 normotensive individuals, assessing correlations between Vitamin D, irisin, blood pressure, and HRV, hypertensive vitamin D deficient participants will be recruited in a randomized controlled trial. In this clinical trial, 60 hypertensive participants with Vitamin D deficiency will receive either Vitamin D supplementation (25,000 IU weekly) or a placebo for 8 weeks (30 participants in each group).

Outcome measures include systolic and diastolic blood pressure, HRV, serum Vitamin D, and serum irisin levels before and after supplementation.

The aim is to explore the potential role of Vitamin D and irisin in regulating blood pressure and improving HRV, potentially offering preventive measures for hypertension management.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Iraq
  • Sulaymaniyah, Iraq, 46001
    • University of Sulaimani, College of Medicine (CoM-UoS)
  • Sulaymaniyah, Iraq
    • Anwar Sheikha Medical City/High quality hospitals
  • Kurdistan region
    • Sulaymaniyah, Kurdistan region, Iraq, 46001
      • Ministry of Higher Education and Scientific research, University of Sulaimani, College of Medicine (CoM-UoS)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Hypertensive: Adult individual diagnosed with hypertension by a specialist (at least two systolic blood pressure readings above 140 mmHg or diastolic blood pressure readings above 90 mmHg, measured by a qualified professional following American Heart Association guidelines) managing hypertension through medication adherence, and regularly attending heart clinic appointments, with no other systemic diseases.

Control: Healthy adult individuals without hypertension or a history of other systemic diseases who volunteer and participate in the study, which will be recruited from relatives, friends, colleagues or patient accompanies. - (*Note: The healthy participants were included in the first part of the study before starting the clinical trial)

Exclusion Criteria:

• 1. Hypertensive individuals who have heart failure and other cardiac or systemic diseases or with recent cardiovascular events.

  2. Secondary hypertension 3. Hypertensive patients who require medication change during the course of the study.

  4. Individuals on Lipid-lowering agents (e.g. simvastatin). 5. The use of other medications affecting blood pressure is not part of the study protocol.

  6. Any subjects on regular supplemental vitamin D or receiving multi-vitamins regularly with vitamin D content of more than 880 IU, one month before recruitment.

  7. Individuals with a BMI over 35 or less than 18 kg/m2. 8. Subjects with a significant change in lifestyle, for example, exercise, weight change, or on a specific dietary regimen during or in the previous four weeks of the study.

  9. Subject diagnosed with neoplasm, or inflammatory or autoimmune diseases 10. Pregnant or lactating female

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Hypertensive Vitamin D deficient individuals receiving placebo capsule; Hypertensive Vitamin D deficient individuals receiving placebo capsules, 1 capsule/week for 8 weeks	Dietary supplement: Placebo Capsule(s); The hypertensive patients with vitamin D deficiency will receive a Placebo capsule. They will be asked to receive a capsule per week for 8 subsequent weeks and re-visit the hospital two weeks from the final dose.
Experimental: Hypertensive vitamin D deficient individuals receiving Vitamin D supplements; Hypertensive Vitamin D deficient individuals receiving Vitamin D capsules, 25,000 IU, 1 capsule/week for 8 weeks	Dietary supplement: Vitamin D (Cholecalciferol ); The hypertensive patients with vitamin D deficiency will receive a Vitamin D capsule with a dose of 25,000 IU. They will be asked to receive a capsule per week for 8 subsequent weeks and re-visit the hospital two weeks from the final dose.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Systolic Blood pressure	This measure will track mean changes in systolic blood pressure in mmHg, before and after 8 weeks of Vitamin D supplementation. The objective is to observe whether there is a significant decrease in systolic blood pressure in hypertensive patients receiving Vitamin D compared to those receiving a placebo.	10 weeks
Diastolic Blood pressure	This measure will assess mean changes in diastolic blood pressure in mmHg, before and after 8 weeks of Vitamin D supplementation. The study aims to determine if there is a significant decrease in diastolic blood pressure in hypertensive patients receiving Vitamin D compared to the placebo group.	10 weeks
Heart rate variability (HRV)	It includes the time domain in milliseconds-ms and frequency domains	10 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serum Irisin	Evaluate changes in mean serum irisin levels in pg/ml or mcg/ml, before and after Vitamin D supplementation in hypertensive patients. The change in mean serum irisin will be correlated with changes in blood pressure and HRV to understand its potential role in cardiovascular regulation.	10 weeks
Serum hydroxycholecalciferol	Measure mean serum 25-hydroxyvitamin D levels to confirm the efficacy of supplementation. The levels will be correlated with the mean of blood pressure, HRV, and serum irisin to explore the impact of Vitamin D repletion.	10 weeks

Collaborators and Investigators

• Sponsor: University of Sulaimani
• Investigators: Principal Investigator: Darya S. Abdulateef, Ph.D., University of Sulaimani/College of Medicine/Branch of Medical Education

Study record dates

Study Major Dates

• Study Start (Actual): November 16, 2024
• Primary Completion (Actual): August 13, 2025
• Study Completion (Actual): August 13, 2025

Study Registration Dates

• First Submitted: October 13, 2024
• First Submitted That Met QC Criteria: October 15, 2024
• First Posted (Actual): October 16, 2024

Study Record Updates

• Last Update Posted (Estimated): August 15, 2025
• Last Update Submitted That Met QC Criteria: August 13, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Vitamin D supplementation; Hypertensive vitamin D deficient; Effect on serum Irisin; Effects on HRV
• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin D Deficiency; Calcium-Regulating Hormones and Agents; Physiological Effects of Drugs; Bone Density Conservation Agents; Micronutrients; Vitamins; Vitamin D; Cholecalciferol
• Other Study ID Numbers: CoM-UoS-308

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No