A new study has confirmed that vitamin D plays an important role in activating your immune defenses against infectious diseases like flu.
Vitamin D deficiency has already been linked to a wide spectrum of diseases including heart disease, cancer, diabetes, depression, autoimmune disease and many others.
The new study discovers that activation of T-cells to fight infections needs definite help from vitamin D. When a T cell recognizes foreign invaders like bacteria or viruses, it sends activating signals to the vitamin D receptor gene. The VDR gene then starts producing DVR protein, which binds vitamin D in the T cell. Then the vitamin D bound and activated DVR produces PLC-gamma1 protein -- which allows the T cell to get started fighting the infection.
Dr. John Cannell has also reported that vitamin D helps produce antibacterial peptides that help protect against flu. That is why in winter, when there is little sunshine, people are more prone to vitamin D deficiency and getting infected with flu viruses.