Vitamin D, the sunshine vitamin, seems to be the nature's best antibiotic, for a new study says that it fends off infections by boosting the immune system. Researchers in Denmark have found that vitamin D, which can be obtained from food or manufactured by human skin<br/><br/>exposed to the sun, triggers and arms the body's T-cells which seek out and destroy any invading bacteria and viruses. According to them, vitamin D is crucial to activating human immune defences and that without its sufficient intake, the killer cells of the immune system, T-cells will not be able to react to and fight off serious infections in the body. For T-cells to detect and kill foreign pathogens such as clumps of bacteria or viruses, the cells must first be triggered into action and transform from inactive and harmless immune cells into killer cells that are primed to seek out and destroy all traces of invaders.<br/>