Vitamin D deficiency tied to hypertension

Low serum levels of 25-hydroxyvitamin D appear to be a risk factor for hypertension, a recent study has shown.

The study included 400 hypertensive patients and 400 age- and sex-matched normotensive participants. Chemiluminescent microparticle immunoassays were used to measure serum 25-hydroxyvitamin D levels. Concentrations of C-reactive protein (CRP) and liver function biomarkers, such as alanine aminotransferase (ALT) and aspartate transaminase (AST), were also measured.

Vitamin D deficiency was significantly more common among hypertensive participants than their comparators (p<0.0001). The same was true for low mean serum calcium (p<0.0001), phosphorous (p<0.0001), and abnormal levels of AST (p=0.0056) and ALT (p=0.0015). Parathyroid hormone concentrations were also significantly raised in hypertensive patients (p<0.0001).

Multivariate analysis confirmed that a deficiency in 25-hydroxyvitamin D levels significantly predicted hypertension (odds ratio [OR], 1.78, 95 percent confidence interval [CI], 1.31–2.41).

Other independent correlates included abnormal ALT (OR, 1.2, 95 percent CI, 0.98–1.94) and AST (OR, 1.1, 95 percent CI, 0.89–1.72), and CRP positivity (OR, 1.48, 95 percent CI, 1.18–2.12). Receiver operating characteristic curve analysis identified an optimum 25-hydroxyvitamin D cutoff of 18 ng/mL, which yielded a sensitivity of 73.4 and a specificity of 54.6.

Moreover, researchers found that patients who had had hypertension for a long time (p=0.02) and had elevated systolic blood pressure (p<0.0001) and diastolic blood pressure (p<0.0001) were more likely to have vitamin D deficiency.