This Trifecta Can Kill You or Save You: Vitamin D, Vitamin K and Vitamin A. A curious, but immensely critical "Triad" of Vitamin D, Vitamin K, and Vitamin A is playing out in our bodies 24/7. The relationship between these three is either adding to your life, or taking from it, with nothing in between. A straight-forward "Adventure in Health" as we travel through this episode!