Low vitamin D linked to unhealthy, stiff blood vessels
Low vitamin D could drive heart disease
New information about vitamin D suggests low levels make arteries stiffer, driving blood pressure higher in people who are otherwise healthy. Poor blood vessel health can increase the risk of heart disease. The findings add evidence that vitamin D is important for overall cardiovascular health.
In study findings, researchers from the Emory/Georgia Tech Predictive Health Institute found boosting vitamin D levels made blood vessels healthier and lowered blood pressure readings in employees from Emory or Georgia Tech.
The findings are presented by Ibhar Al Mheid, MD, a cardiovascular researcher at Emory University School of Medicine, at the annual American College of Cardiology meeting in New Orleans and included 554 generally healthy adults, whose average age was 47.
Lack of vitamin D impairs blood vessel health same as diabetes
According to Dr. Al Mheid, "We found that people with vitamin D deficiency had vascular dysfunction comparable to those with diabetes or hypertension," even after controlling for other factors such as age, weight and cholesterol.
The endothelium is the lining of the arteries. Arteries, veins and capillaries are located throughout the body and arteries are the main suppliers of oxygen rich blood.
When arteries become stiff and the lining is damaged, the chances of developing blood clots increases. Stiff arteries lead to impaired blood flow that can affect every organ of the body, boosting the chances of stroke, heart attack, kidney dysfunction and peripheral artery disease.
Boosting vitamin D relaxes blood vessels in study
In the study, boosting vitamin D levels was found to relax the blood vessels. The researchers testing the effect by cutting off blood flow in the arms of the study group then measured how well blood flow returned to the extremity using ultrasound.
Participants who raised their vitamin D levels by increased sun exposure or supplements had improved blood vessel health and dropped their readings an average of 4.6 points. Employees with low vitamin D had stiff arteries that are seen with diabetes and hypertension.
Among the study group, 14 percent had 25-hydroxyvitamin D levels considered deficient and 33 percent had levels considered insufficient. Deficiency is less than 20 nanograms per milliliter. Insufficient vitamin D is 30 nanograms per milliliter, though there is much discussion about how much of the vitamin is needed for optimal health.
The researchers also measured resistance to blood flow in the smaller blood vessels that occurs when arteries are constricted.
Al Mheid says it may be that vitamin D has a hormonal influence on blood vessels that keeps them relaxed and healthy. It might also be a strengthening effect on the muscles that surround arteries. The hormone angiotensin increases blood pressure and vitamin D may lower angiotensin levels he says.
The findings have implications for maintaining blood vessel health that declines with aging. Reducing the risk of high blood pressure, heart attack and stroke could come from ensuring vitamin D levels are adequate.
The researchers plan a follow-up study using a specific vitamin D dose. Because the study was observational, the researchers were unable to evaluate how the employees boosted their vitamin D levels to improve blood vessel health.
Source: Emory University
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