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

Abstract EN

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).