Friday fact: Vitamin K is a fat soluble vitamin essential for coagulation of blood and wound healing. It naturally occurs in leafy vegetables such as broccoli and kale. It's name is derived from the German word Koagulation. Vitamin K is a crucial ingredient used by the liver to produce proteins that help with haemostasis of the blood. A deficiency in vitamin k can lead to bruising and prominent, fragile veins. Vitamin k compounds can help prevent and reduce the appearance of dark circles and puffiness around the eyes, spider veins and stretch marks.