Does Vitamin D Provide Added Benefit To Antihypertensive Therapy In Reducing LVH Determined By CMR?

BACKGROUND: Left ventricular hypertrophy (LVH) and vitamin D deficiency have been linked to hypertension (HTN) and cardiovascular disease, particularly in African Americans (AAs). Our objective was to determine if the addition of vitamin D to antihypertensive therapy would lead to greater regression of LV mass index (LVMI) as determined by cardiac magnetic resonance (CMR) after 1-year in vitamin D deficient AA patients with uncontrolled HTN and LVH.

METHODS: This study was a randomized, double-blind, placebo-controlled, single-center study. AA patients with HTN (systolic BP>160mmHg), increased LVMI by CMR, and vitamin D deficiency (<20 ng/mL) were randomized into vitamin D treatment and placebo groups. All randomized patients received antihypertensive therapy combined with bi-weekly 50,000 IU vitamin D3 (vitamin D group, n=55; 43 completed) or placebo (placebo group, n=58; 49 completed).

RESULTS: Across all patients, mean LVMI was 97g/m 2. At 1-year, there were no statistical differences between the vitamin D and placebo groups in LVMI (-14.1±14.6g/m 2 vs. -16.9±13.1g/m 2; p =0.34) or systolic BP (-25.6±32.1 vs. -25.7±25.6 mm Hg; p=0.99) reduction, respectively. Serum vitamin D levels increased significantly in the vitamin D group compared to placebo (12.7±2.0 vs. 1.8±8.2ng/mL; p<0.001).

CONCLUSIONS: In this high-risk cohort of AAs with poorly controlled HTN, vitamin D deficiency, and LVH, we did not find an association between vitamin D supplementation and differential regression of LVMI or reduction in systolic BP. However, our study suffered from a small sample size with low statistical power precluding a definitive conclusion on the therapeutic benefit of vitamin D in such patients.