"Vitamin D protects you from flu, Oxford scientists find" https://www.sciencedirect.com/science/article/abs/pii/S0002916525007713 Low vitamin D levels linked to 33% higher risk of hospitalization for severe respiratory infections https://www.telegraph.co.uk/news/2026/01/21/vitamin-d-protects-you-from-flu-oxford-scientists-find/ Researchers analysed NHS data from 36,258 people to undertake the study