ISLAMABAD: Taking extra vitamin D can protect against colds, flu and other respiratory infections, said a study which reopened a debate on the usefulness of over-the-counter supplements.
According to a private news channel, a review of 25 clinical trials in 14 countries, some with conflicting results, yielded “the first definitive evidence” of a link between vitamin D and flu prevention, researchers claimed in The British medical journal.
The effects were strongest for people with very low levels of the nutrient which is found in some foods and can be synthesised by the body when the skin is exposed to ultraviolet light.
Scientists said that low levels of the vitamin increase the risk of bone fractures, heart disease, colorectal cancer, diabetes, depression, Alzheimer’s disease and death.
Others said there is no evidence of a link to disease risk.
Vitamin D is thought to protect against respiratory infections, including bronchitis and pneumonia, by boosting levels of antibiotic-like peptides in the lungs, said the team.
This fits with an observation that colds and flu are more common in winter and spring, when vitamin D levels are lowest.—APP