K2D3 is your go-to vitamin D supplement to support your heart, bones, muscles, and mood. Vitamin D3 is that important, and it needs Vitamin K2 to maximize all those benefits. With an estimated 1 billion people worldwide experiencing Vitamin D deficiencies, supplementing is an effective solution—especially if you get less sun exposure during those winter months. Zhou's premium formulation packs a punch with 5000 IU per serving and the most bioavailable form of K2 available (mk-7).