We are all aware that most of us are Vitamin D deficient. For cold and flu season you should be taking a supplement if your levels are below the 60-80ng/ml. Rick explains that Vitamin D is an immune modulator which means that it can both boost and calm down the immune system depending on what our bodies need. Vitamin D also restores telomere length which keeps us from aging too fast. This video will make you appreciate just how amazing Vitamin D is for our health!