More than three million people across the UK could stave off infections such as colds or flu every year if everyone took Vitamin D supplements, experts have said.
A new study has found taking the supplements protects against acute respiratory infections.
Vitamin D supplements has been a hot topic in medical circles in recent years with some experts arguing that their usefulness remains uncertain.
But health officials say that vitamin D is vital for bone and muscle health.
Last year, Public Health England said that people were generally not getting the recommended 10 micrograms of vitamin D a day from sunlight in winter.
The latest new study, published in The BMJ, suggests that taking vitamin D – also known as the sunshine vitamin – may have benefits beyond bone and muscle health and protects against acute respiratory infections.
Results of the study fit with the observation that colds and flu are most common during winter and spring, when levels of vitamin D are lowest.
Respiratory tract infections are any infection of the sinuses, throat, airways or lungs and can last up to 30 days.
The common cold is the most widespread respiratory tract infection; others include ear infections, bronchitis and pneumonia.
At least 70 per cent of the population gets at least one every year. About a quarter of the UK population will visit the GP each year to get treatment. Acute respiratory infections lead to 300,000 hospital admissions and they lead to 35,000 deaths across the UK every year.
The new research, led by academics from Queen Mary University of London, analysed data from almost 11,000 participants aged up to 95 who took part in 25 clinical trials conducted in 14 countries, including the UK.
The study concluded that supplements can help prevent acute respiratory tract infections, particularly among those who are deficient in vitamin D.
The researchers found that vitamin D supplementation cut the proportion of participants experiencing at least one acute respiratory tract infection by 12 per cent.