Scientists at Wisconsin University have discovered the H1N1 swine flu causes more inflammation than seasonal flu, the Sun report said.
Swine flu also works its way deeper into the lungs, making it more likely to trigger complications such as pneumonia.
And previous studies have shown vitamin D - which our bodies make from sunshine - protects against a number of inflammatory conditions including heart disease, multiple sclerosis and rheumatoid arthritis.
Experts at Harvard Medical School found asthmatic kids are 'significantly' more likely to be hospitalised if they also have low levels of the vitamin.
According to Dr John Cannell, from the University of Washington, it is no accident colds and flu peak in winter - that's because of lack of sunlight, which means vitamin D deficiency in the body. And he is sure the sunshine vitamin could be the key to avoiding a severe bout of swine flu.