Vitamin K

Compounds are fat soluble napthoquinones.

Vitamin K1, also known as phylloquinone, is a fat-soluble vitamin that plays a key role in blood clotting and bone metabolism.

It is found naturally in some plant-based foods such as green leafy vegetables: spinach, kale, collard greens, broccoli), vegetable oils, and some fruits.

Phytonadione, vitamin K1, and vitamin K2 occur in foods and synthesized by certain bacteria in the gastrointestinal tract.

 Vitamin K1 is essential for the synthesis of the protein  prothrombin, which is important in the formation of blood clots. 

It is also involved in the production of other important proteins that help with bone health. 

Vitamin K1 is known to prevent excessive bleeding from wounds and injuries by facilitating the clotting of blood, and it may also reduce the risk of osteoporosis by helping to maintain healthy bones.

Found in dark, leafy green plants.

Found in green tea, kale, broccoli, turnips, spinach, lettuce, cabbage, and beef and prok lier.

Cigarettes have high content and smoking should avoided when taking warfarin.

Commercially prepared phytonadione has the same the activity associated naturally occurring vitamin K1.

Necessary for synthesis of factors II, VII, IX and X by the liver.

Deficiency seen with biliary obstruction, and conditions limiting absorption of vitamin K from the gastrointestinal tract including celiac disease, ulcerative colitis, sprue, regional enteritis cystic fibrosis, intestinal resection and in patients receiving drugs that may affect intestinal flora or liver function.

Absorbed from the gastrointestinal tract in the presence of bile salts and pancreatic lipase.

After absorption accumulates in the liver, spleen and lungs without significant storage.

Absorption enhanced by fat in the diet.

Amount synthesized by bacteria is insufficient for bodily needs.

Necessary for the production of protein C and S.

After participating in formation of coagulation factors, vitamin K epoxide is converted to the active form vitamin K hydroquinone.

Cofactor in the reaction whereby gamma carboxylase catalyzes production of factors II, VII, IX, X , protein C and S.

Deficiency results from inadequate intake, fat malabsorption, or use of warfarin.

Deficiency common in breastfed infants.

Deficiency causes hemorrhagic disease of the newborn, which usually occurs 1 to 7 days postpartum.

Newborns prone to vitamin K deficiency because the placenta transmits lipids, and vitamin K relatively poorly, the neonatal liver is immature with respect to prothrombin synthesis and breast milk is low in vitamin K, and the newborn gut is sterile for the first few days of life.

Deficiency may be associated with late hemorrhagic disease in infants 3-8 weeks of age and may be associated with breast feeding, malabsorption or liver disease.

Subcutaneous administration for excessive anticoagulation does not reverse the process as fast as intravenous administration but has less risk of anaphylaxis.

May have a role in treating hypoprothrombinemia induced by salicylates, quinidine, sulfonamides, or broad spectrum antibiotics when interference with vitamin K activity occurs.

Severe reactions may follow intravenous injections, including fatalities and such use should be restricted to situations where other routes are not feasible and risk is justified.

Hypoprothrombinemia resulting from hepatocellular damage is not corrected by vitamin K administration.

Repeated doses of vitamin K not warranted in liver disease if response to initial use is unsatisfactory.

Diet high in vitamin K can block effects of oral anticoagulants.

Promotes synthesis of prothrombin but does not directly reverse the effects of oral anticoagulants.

Not a clotting agent but overzealous use of phytonadione may increases risk of thromboembolism.

Incidence of deficiency higher in breast fed newborn infants compared to those given cow’s milk formula.

Recommended that all newborns receive vitamin K prophylaxis.

Large amounts of vitamin K given during pregnancy can lead to neonatal jaundice.

The use of broad spectrum antibiotics, quinidine, quinine and high doses of aspirin can increase vitamin K requirements.

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