Effect of Short-Term Vitamin D3 Supplementation on Blood Pressure in Patients With Hypertension: A Pilot Study From a Tertiary Care Hospital

Background Essential hypertension is a major risk factor for cardiovascular disease. Emerging evidence suggests that vitamin D deficiency may contribute to the development of essential hypertension through mechanisms involving the renin-angiotensin-aldosterone system and vascular endothelial dysfunction. However, the effect of vitamin D3 supplementation on blood pressure remains controversial. Hence, this study aimed to evaluate the effect of short-term oral vitamin D3 supplementation on blood pressure in patients with essential hypertension. Methodology This prospective, interventional pilot study included 30 adult patients diagnosed with essential hypertension. All participants received oral vitamin D3 (250 IU daily) for 12 weeks, in addition to stable antihypertensive therapy. Antihypertensive medications (including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, and diuretics) were continued without any dose modification during the study period. Systolic blood pressure, diastolic blood pressure, and serum 25-hydroxyvitamin D levels were measured at baseline and after 12 weeks of intervention. Data were expressed as median (interquartile range). The Wilcoxon signed-rank test was used for paired comparisons. Results Among the 30 participants, 12 (40%) had normal vitamin D levels, 11 (36.7%) had insufficiency, and seven (23.3%) had deficiency at baseline. After 12 weeks of vitamin D3 supplementation, systolic blood pressure decreased from 133 (130-138) mmHg to 132 (130-136) mmHg, and diastolic blood pressure decreased from 94 (92-96) mmHg to 92 (90-95.5) mmHg (p < 0.001 for both). Serum 25-hydroxyvitamin D levels increased from 27 (20.25-31) ng/mL at baseline to 28 (23-32) ng/mL after supplementation in essential hypertension patients (p < 0.001). Despite being statistically significant, the absolute reductions in blood pressure were small. Conclusions Short-term vitamin D3 therapy was associated with a small reduction in blood pressure of uncertain clinical significance among patients with essential hypertension. Due to the absence of a control group, causality cannot be established. These findings should be considered exploratory, and larger randomized controlled studies are necessary to confirm these results.