University of Leeds
A daily dose of vitamin D3 improves heart function in people
with chronic heart failure, a five-year University of Leeds research project
has found.
Dr Klaus Witte, from the School of Medicine and Consultant
Cardiologist at Leeds Teaching Hospitals NHS Trust, led the study, known as
VINDICATE.
He said: "This is a significant breakthrough for patients.
It is the first evidence that vitamin D3 can improve heart function of people
with heart muscle weakness -- known as heart failure. These findings could make
a significant difference to the care of heart failure patients."
Vitamin D3 can be boosted by exposure to sunlight, but heart failure patients are often deficient in it even during the summer because older people make less vitamin D3 in response to sunlight than younger people. Vitamin D3 production in the skin is also reduced by sunscreen.
The study, which was funded by the Medical Research Council,
involved more than 160 patients from Leeds who were already being treated for
their heart failure using proven treatments including beta-blockers,
ACE-inhibitors and pacemakers.
Participants were asked to take vitamin D3 or a dummy (placebo)
tablet for one year. Those patients who took vitamin D3 experienced an
improvement in heart function which was not seen in those who took a placebo.
Changes in heart function were measured by cardiac ultrasound.
Heart specialists measure heart function by taking an ultrasound scan of the
heart (known as an echocardiogram) and measuring how much blood pumps from the
heart with each heartbeat, known as ejection fraction.
The ejection fraction of a healthy person is usually between 60%
and 70%. In heart failure patients, the ejection fraction is often
significantly impaired -- in the patients enrolled into the VINDICATE study the
average ejection fraction was 26%.
In the 80 patients who took Vitamin D3, the heart's pumping
function improved from 26% to 34%. In the others, who took placebo, there was
no change in cardiac function.
This means that for some heart disease patients, taking vitamin
D3 regularly may lessen the need for them to be fitted with an implantable
cardioverter defibrillator (ICD), a device which detects dangerous irregular
heart rhythms and can shock the heart to restore a normal rhythm.
"ICDs are expensive and involve an operation" said Dr
Witte. "If we can avoid an ICD implant in just a few patients, then that
is a boost to patients and the NHS as a whole."
One key aspect of this study is that the researchers avoided
using a calcium-based supplement, as calcium can cause further problems for
heart failure patients.
The findings from the VINDICATE study will be presented at the
American College of Cardiology 65th Annual Scientific Session & Expo in
Chicago on April 4.
Heart failure affects about 900,000 people in the UK and more
than 23 million worldwide.
The condition can affect people of all ages, but it is more
common in older people -- more than half of all people globally with heart
failure are over the age of 75.