Define Absorption, Storage and Elimination of Vitamin K?

Dietary vitamin K, mainly phylloquinone, is absorbed chemically unchanged from the proximal intestine after solubilization into mixed micelles composed of bile salts and the products of pancreatic lipolysis. In healthy adults, the efficiency of absorption of phylloquinone in its free form is about 80%. Within the intestinal mucosa, the vitamin is incorporated into chylomicrons, is secreted into the lymph, and enters the blood via the lacteals (minute intestinal lymph-carrying vessels). Once in the circulation,  phylloquinone is rapidly cleared at a rate consistent with its continuing association  with chylomicrons and the chylornicron remnants, which are produced by lipoprotein  lipase hydrolysis at the surface of capillary endothelial cells. Although phylloquinone is the major circulating form of vitamin K, MK-7 is also present in plasma, at lower concentrations and with a lipoprotein distribution similar to phylloquinone.

Vitamin K is stored in the liver - the site of synthesis of coagulation proteins -and of 90 percent menaquinones. Phylloquiucnes and menaquinones are also extra hepatic tissues. Phylloquinone levels are high in liver, heart and pancreas. Vitamin K is extensively metabolized in the liver and excreted in the urine and bile. About 60-70% of the amount of' phylloquinone absorbed from each meal will ultimately be lost to the body by excretion. This, therefore, suggests that the body stores of phylloquinone are being constantly replenished.