Vitamin D Important for Vascular Health

Vitamin D enhances vascular function and optimal blood flow, a recent study reports. The endothelial cells are located along the inner lining of blood vessels and play an important role in regulating blood flow through the blood vessels. Over time, excess fat, calcium and cholesterol deposits can accumulate on artery walls, affecting the health of the vessels and resulting in imbalanced blood flow. Narrowing of the blood vessel also causes the fluid in the vessel to move at a higher pressure, which can further affect the vessel.

Serum 25-hydroxyvitamin D was measured in 554 subjects. The subjects were evaluated for brachial artery flow-mediated dilation, which measures blood flow through the arm and assesses endothelial function, and digital reactive hyperemia, which measures microvascular function. Arterial health was evaluated using carotid-femoral pulse wave velocity and radial tonometry-derived central augmentation index, and subendocardial viability ratio, which evaluated oxygen supply and demand in the heart muscle.

The study found that serum 25-hydroxy­vitamin D correlated to flow-mediated vasodilation, reactive hyperemia index, pulse wave velocity, augmentation index, and subendocardial viability ratio. This means that vitamin D is related to endothelial function and arterial health. Even after adjusting the data to account for potential confounding factors such as age, sex, race, body mass index (BMI), total cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, C-reactive protein (CRP), and medication use, the correlation between serum 25-hydroxyvitamin D and endothelial function and arterial health remained significant.

Additionally, in 42 subjects with vitamin D insufficiency, normalization of the serum 25-hydroxyvitamin D over 6 months resulted in beneficial changes in the reactive hyperemia index and subendocardial viability ratio, as well as optimized the mean arterial blood pressure.

The researchers concluded that vitamin D sufficiency is associated with arterial health and endothelial function in the conductance and resistance blood vessels in humans, irrespective of traditional associated cardiovascular factors.

Reference:

Al Mheid I, Patel R, Murrow J, Morris A, Rahman A, Fike L, Kavtaradze N, Uphoff I, Hooper C, Tangpricha V, Alexander RW, Brigham K, Quyyumi AA. Vitamin d status is associated with arterial stiffness and vascular dysfunction in healthy humans. J Am Coll Cardiol. 2011 Jul 5;58(2):186-92.