If you ask anybody that takes 5000 units of vitamin D every day, they will tell you they just don’t get sick anymore, it just doesn’t happen. How that works is- Your body makes natural incurring antibiotics, and Vitamin D regulates and increases production of these natural antibiotics. Of course that makes sense, do you generally get colds or flu’s in the summertime? This is more common in the wintertime because your body produces less than one third of vitamin D than it does in the summer. Scientists confuse facts with theories. For example, people get more heart attacks in the winter because they are shovelling snow, or because of influenza.. the fact is people get more heart attacks in the winter, everything else is theory. Over 100 years ago, every doctor knew that the sunshine was a cure for tuberculosis because of the vitamin D. Any infectious disease is more common in the winter time, as a target of vitamin D.