Clinical Question

Does treatment with vitamin D lower blood pressure in older patients with isolated systolic hypertension and low vitamin D levels?

Bottom Line

Vitamin D supplementation in patients with isolated systolic hypertension and low levels of vitamin D does not decrease systolic blood pressure after one year of treatment. (Level of Evidence = 1b)

Synopsis

Because low vitamin D levels are associated with hypertension, Scottish researchers investigated the role of vitamin D supplementation in 159 patients, at least 70 years of age, with isolated systolic hypertension greater than 140 mm Hg and vitamin D levels (25-hydroxyvitamin D) of less than 30 ng per mL (75 nmol per L). Using concealed allocation, patients were randomized to receive oral placebo or cholecalciferol at a dosage of 100,000 IU every three months for one year. As expected, vitamin D levels increased an average of 8 ng per mL (20 nmol per L) in the treated patients. Systolic blood pressure, though, did not significantly change or differ between the groups (0.8 mm Hg). Similarly, other measures—24-hour blood pressure, arterial stiffness, endothelial function—did not change.

Study design: Randomized controlled trial (double-blinded)

Funding source: Government

Allocation: Concealed

Setting: Outpatient (any)

Reference: Witham MD, Price RJ, Struthers AD, et al. Cholecalciferol treatment to reduce blood pressure in older patients with isolated systolic hypertension: the VitDISH randomized controlled trial [published ahead of print August 12, 2013]. JAMA Intern Med. http://archinte.jamanetwork.com/article.aspx?articleid=1726994. Accessed October 4, 2013.