High-Dose versus Low-Dose Vitamin D Supplementation and Arterial Stiffness among Individuals with Prehypertension and Vitamin D Deficiency.

Amanda Zaleski,Thomas Wang,Paul D Thompson,Christopher Newton-Cheh,Gregory Panza,Heather Swales,Beth Taylor,Pankaj Arora

doi:10.1155/2015/918968

Abstract

Introduction. Vitamin D deficiency is associated with the onset and progression of hypertension and cardiovascular disease (CVD). However, mechanisms underlying vitamin D deficiency-mediated increased risk of CVD remain unknown. We sought to examine the differential effect of high-dose versus low-dose vitamin D supplementation on markers of arterial stiffness among ~40 vitamin D deficient adults with prehypertension. Methods. Participants were randomized to high-dose (4000 IU/d) versus low-dose (400 IU/d) oral vitamin D3 for 6 months. 24 hr ambulatory blood pressure (BP), carotid-femoral pulse wave velocity, and pulse wave analyses were obtained at baseline and after 6 months of vitamin D supplementation. Results. There were no changes in resting BP or pulse wave velocity over 6 mo regardless of vitamin D dose (all p > 0.202). High-dose vitamin D decreased augmentation index and pressure by 12.3 ± 5.3% (p = 0.047) and 4.0 ± 1.5 mmHg (p = 0.02), respectively. However, these decreases in arterial stiffness were not associated with increases in serum 25-hydroxyvitamin D over 6 mo (p = 0.425). Conclusion. High-dose vitamin D supplementation appears to lower surrogate measures of arterial stiffness but not indices of central pulse wave velocity. Clinical Trial Registration. This trial is registered with www.clinicaltrials.gov (Unique Identifier: NCT01240512).

Highlights

Vitamin D deficiency is associated with the onset and progression of hypertension and cardiovascular disease (CVD)
The purpose of the present study was to determine the influence of high-dose and low-dose vitamin D supplementation on markers of arterial stiffness and mean 24 hr blood pressure (BP)
These results suggest that the pleiotropic, beneficial effect of vitamin D on markers of arterial stiffness may be dosedependent and that previous inconsistencies in the literature regarding vitamin D and CVD outcomes may be attributable in part to a differential treatment effect of vitamin D dosage

Summary

Introduction

Vitamin D deficiency is associated with the onset and progression of hypertension and cardiovascular disease (CVD). High-dose vitamin D decreased augmentation index and pressure by 12.3 ± 5.3% (p = 0.047) and 4.0 ± 1.5 mmHg (p = 0.02), respectively These decreases in arterial stiffness were not associated with increases in serum 25-hydroxyvitamin D over 6 mo (p = 0.425). Of most recent interest is the association between vitamin D deficiency and major cardiovascular disease (CVD) risk factors, including hypertension [4, 7,8,9]. Mechanisms underlying vitamin D deficiency-mediated increased risk of hypertension are not clear but may be related to arterial stiffness, a well-documented independent predictor of incident hypertension [11], CVD related events [12], and all-cause mortality [13, 14]. It is possible that underlying changes in arterial stiffness may partially explain the reported associations among vitamin D status, blood pressure (BP), and CVD risk

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