A daily dose of vitamin D can improve the blood-pumping performance of damaged hearts, a study has found.
Researchers studied 160 patients being treated for heart failure using a variety of proven drug treatments and pacemakers.
Participants who took a vitamin D3 supplement daily for one year experienced an improvement in heart function not seen in those given a dummy pill.
Lead scientist Dr Klaus Witte, from the School of Medicine at Leeds Teaching Hospitals NHS Trust, 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."