Effect of Vitamin D Replacement During Winter Months in Patients With Hypertension

Effect of Cholecalciferol on 24-hr ABPM and Vasoactive Hormones in Patients With Hypertension.

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01166165

Enrollment

136

Registered

2010-07-20

Start date

2010-07-31

Completion date

2011-04-30

Last updated

2012-06-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hypertension, Vitamin D Deficiency

Keywords

Hypertension, blood pressure, vitamin d, winter, cholecalciferol, arterial stiffness, renin, angiotensin, aldosterone, calcium

Brief summary

High blood pressure is related to increased risk of cardiovascular disease and death, and accounts for approximately 8 mill deaths worldwide each year. Blood pressure exhibits a seasonal variation with a tendency to increase during winter months. Vitamin D deficiency is more common during months where UVB radiation from the sun is absent, and vitamin D has been associated with high blood pressure. This study will evaluate the effect of vitamin D replacement during winter months on blood pressure and vasoactive hormones in patients with high blood pressure.

Interventions

DRUGCholecalciferol

3 tablets of 1000 IU daily for 20 weeks

DRUGPlacebo

3 placebo tablets daily for 20 weeks

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Well-regulated arterial hypertension * Office blood pressure \> 120/70 mmHg

Exclusion criteria

* Pregnancy or nursing * Cancer * Alcohol abuse * Continuous glucocorticoid or NSAID treatment * 24-hour blood pressure \> 150/95 mmHg * Hypercalcemia

Design outcomes

Primary

Measure	Time frame
24-hour systolic blood pressure	20 weeks

Secondary

Measure	Time frame
Plasma concentration of angiotensin II	20 weeks
Plasma concentration of aldosterone	20 weeks
Plasma concentration of c-reactive protein	20 weeks
Urine albumin creatinine ratio	20 weeks
Urine calcium creatinine ratio	20 weeks
Plasma concentration of 25-hydroxycholecalciferol	5 weeks
Plasma renin concentration	20 weeks
Augmentation index and central blood pressure	20 weeks
Pulse wave velocity	20 weeks
Heart rate variability	20 weeks
Plasma concentration of ionized calcium	5 weeks
Plasma concentration of phosphate	5 weeks
Serum concentration of FGF-23	20 weeks

Countries

Denmark

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026