Solgar Vitamin K1 (Phytomenadione) 100 mcg Tablets contains Vitamin K, a fat-soluble vitamin. There are 3 types of Vitamin K; K1 (Phytomenadione) is derived from food, K2 (Menaquinone) is produced by intestinal bacteria and K3 (Menadione) is a synthetic form. Vitamin K is important for blood clotting or coagulation and is essential for the synthesis by the liver of blood clotting proteins. Vitamin K is also widely recognised for supporting healthy bones. This is due to its ability to activate calcitonin, a hormone produced by humans, which then aids the absorption of Calcium into the bone. Absorption of Vitamin K takes place mainly in the upper part of the small intestine with the help of bile or bile salts and pancreatic juices and then carried to the liver.Vitamin K is found in both plant and animal sources in nature, with high concentrations found in dark leafy greens liver, milk and fish liver oils. 100 mcg Vitamin K1 has a 1 tablet a day dose, providing you with this key vitamin, contributing to: Normal blood clotting Maintenance of normal bones