Oxford Scientists Discover Vitamin D's Powerful Flu Protection

Getting enough vitamin D really can help to protect you against the flu, a study has found. It revealed that people with a severe vitamin D deficiency were 33 per cent more likely to be admitted to hospital with a respiratory tract infection than those who were receiving adequate amounts. Vitamin D is the only supplement recommended by the NHS for everyone during winter months, when exposure to sunlight, which the body uses to produce the nutrient, is limited. It is already known to help regulate the amount of calcium and phosphate in the body, which is vital for bone and muscle health, but experts also believe it may have antiviral properties. To test this theory, researchers from the Universities of Surrey, Oxford and Reading analysed data on 36,000 British adults to find out how levels of vitamin D in the body affected the rate of hospital admission with respiratory infections. These included a range of viral and bacterial illnesses such as flu, pneumonia and bronchitis. Previous studies have linked vitamin D deficiency to increased risk of severe Covid, another respiratory infection. The results from this latest study – the largest to date – revealed that people with a severe vitamin D deficiency, classed as having a concentration below 15 nanomoles per litre (nmol/L) in the blood were 33 per cent more likely to be admitted to hospital for respiratory infections than those with optimal levels of more than 75nmol/L. The experts found that for each 10 nmol/L increase in vitamin D, the hospital admission rate for respiratory tract infections fell by 4 per cent. Overall, some 2,255 patients were admitted to hospital with a respiratory infection out of the 27,872 people included in the final analysis. Middle-aged and older people are particularly susceptible to ending up in hospital with respiratory tract infections such as pneumonia. The NHS advice is for people to take a daily 10 microgram vitamin D supplement during the autumn and winter when a lack of sun can lead to deficiency. Vitamin D is also found in some foods such as oily fish, red meat, egg yolks and fortified cereals. Abi Bournot, lead author from the University of Surrey, said that receiving at least 10 micrograms of the vitamin a day “especially in the autumn and winter when sunlight is limited, is important to help prevent vitamin D deficiency”, which is considered as below 25 nmol/L in the blood. “Vitamin D is vital to our physical wellbeing,” she continued. “Not only does it keep our bones and muscles healthy, it is antibacterial and antiviral properties are also thought to help reduce the risk of respiratory tract infections that can lead to hospitalisation”. “This research attaches hard data to support the theory. Despite its importance to our overall health, many people are deficient and do not meet the Government’s recommended intake of 10 micrograms of vitamin D per day.” “Supplementation of the vitamin, especially in the winter months when our exposure to sunlight is limited, is an effective way of increasing vitamin D and reducing the risk of serious respiratory tract infections. “This is particularly important for older people who are at higher risk of death from such infections, and ethnic minority communities in the UK, who are at a higher risk of vitamin D deficiency.” The study was published in the American Journal Of Clinical Nutrition.