Vitamin D: Blood Pressure Ally or Risk?

Vitamin D is emerging as a key factor in cardiovascular health, influencing blood pressure management when combined with common antihypertensive drugs. It plays a vital role in regulating vascular tone and the renin-angiotensin-aldosterone system (RAAS), which controls blood pressure.

When taken with ACE inhibitors or ARBs, vitamin D often exhibits a synergistic effect, enhancing blood vessel relaxation and improving blood pressure control. This combination is generally considered safe and clinically advantageous for many patients.

Conversely, interactions with other drug classes require caution. High-dose vitamin D alongside thiazide diuretics can elevate serum calcium, potentially straining the kidneys. Similarly, extremely high doses might affect the efficacy of calcium channel blockers by altering circulating calcium levels.

Patients on any blood pressure medication should consult their cardiologist before starting vitamin D supplementation. Baseline testing of serum calcium and 25-hydroxyvitamin D levels is recommended, along with regular monitoring to prevent adverse effects like hypercalcaemia or unexpected fluctuations in blood pressure.