High Vitamin D dose may rapidly cut arterial stiffness

Cardiovascular diseases are the leading cause of death globally, with an estimated 17.7 million deaths in 2015, and representing 31 per cent of all global deaths.

The findings showed that the dose of 4,000 international units (IUs)-- more than six times the daily 600 IUs currently recommended for most adults and children -- now considered the highest, reduced arterial stiffness the most and the fastest, 10.4 per cent in four months. 

Two thousand IUs decreased stiffness by two per cent in that timeframe. 

"When your arteries are more stiff, you have higher pulse wave velocity, which increases your risk of cardiometabolic disease in the future," said Anas Raed, research resident at the varsity.

For the study, detailed in the journal PLOS ONE, the team looked at African-Americans aged 13-45 -- all of whom had some degree of arterial stiffness -- taking varying doses of the vitamin best known for its role in bone health.

While just how Vitamin D is good for our arteries is not completely understood, it appears to impact blood vessel health in many ways, the researchers said.

Laboratory studies have shown that mice missing a vitamin D receptor have higher activation of the renin-angiotensin-aldosterone system, activation of which increases blood vessel constriction, that can contribute to arterial stiffness. 

Vitamin D also can suppress vascular smooth muscle cell proliferation, activation of garbage-eating macrophages and calcification formation, all of which can thicken blood vessel walls and hinder flexibility. 

Vitamin D also reduces inflammation, an underlying mechanism for obesity related development of coronary artery disease, Raed said.