Vitamin D supplements don't help ward off colds and flus, new research finds By Jessica Stewart ThuThursday 14 JanJanuary 2021 at 3:10am The five-year trial found unless a person was vitamin D deficient, supplements won't help Australians ward off colds and flus. ( Share Print text only Cancel Vitamin D supplements will not protect Australians from catching colds, flus and other respiratory infections, new research has found. Key points: 2,600 participants were asked to keep a daily diary Results found some indication that supplements can reduce the length and severity of illnesses The findings come after a five-year clinical trial, led by Brisbane's QIMR Berghofer Medical Research Institute, involving 16,000 Australians aged between 60 and 84.