Headlines
As reported by Health Jockey, November 26, 2009.
Physicians Investigate Apparent Link Between Vitamin D Deficiency and Hypertension
Vitamin D is known to be important to bone health, but what about heart health? University of Connecticut Health Center physician-scientists are believed to be looking into a potential link between vitamin D deficiency and high blood pressure.
For the purpose of the study, Dr. White and Dr. Pooja Luthra, assistant professor of medicine and an endocrinologist in the New England Musculoskeletal Institute, seem to be recruiting patients with a diagnosis of treated or untreated high blood pressure and a vitamin D level in the inadequate range of 12 to 29. Moreover, these patients should not be consuming regular doses of vitamin D.
Chief author of the study, Dr. William B. White, professor of medicine and a hypertension expert in the Pat and Jim Calhoun Cardiology Center, says "Often patients don’t realize they have a vitamin D deficiency, or are unaware of its relationship with health problems other than bone disorders."
Epidemiologic studies apparently have revealed an association between measured vitamin D deficiency and increased risk for incident hypertension. More so, hypertension is known to be independent of age, body mass index, physical activity, race, and menopausal status. There seems to be a requirement for clinical studies that assess the effects of antihypertensive drugs in hypertensive patients with recognized vitamin D insufficiency.
"One of the possible mechanisms of elevated blood pressure in patients with vitamin D deficiency is the activation of renin, an enzyme produced in the kidney," says Dr. White.
Study involving genomic mouse models found that those with vitamin D deficiency seem to have developed elevated production of renin and the protein angiotensin II thereby resulting in hypertension. In the 14-week, double-blind, randomized trial, participants will perhaps initially receive vitamin D replacement or the renin inhibitor aliskiren, then both medicines in combination.
White further said that, "We have reason to believe there’s a connection here, and this research will increase our knowledge regarding vitamin D as a cardiovascular risk factor. We will try to establish the effects of vitamin D replacement and the impact of direct inhibition of renin in patients with vitamin D deficiency on blood pressure. In the end, we hope that we can spread awareness about the association so that if patients with hypertension ask their doctors, ‘What if I have vitamin D deficiency?’ then their doctors will be prepared to make informed decisions about what to do about this problem."
Further, White and Luthra will assess the equivalent changes in blood pressure both in the office setting and over a 24-hour period. This may be measured via ambulatory blood pressure monitoring, calcium and vitamin D concentrations, and biochemical parameters involving the renin-angiotensin system.