Vitamin D3 is a fat soluble vitamin that is vital to improve the absorption of Calcium and Phosphate in the body. When Vitamin D3 is combine with K2 it improves the overall effectiveness in its ability to support strong and healthy bone development. The combination of D3 & K2 has also been shown to improve the immune and cardiovascular system, brain health, muscle function & provides additional antioxidant support to protect the body from free radicals. Metabolic Nutrition provides a purified, all natural, highly concentrated, Vitamin D3 & K2 formula for maximum effectiveness & absorption... specifically developed for individuals who want to maximize their health and wellness.