NOTE: Please consult with your doctor before changing your diet or taking supplements.
Vitamin K is a fat-soluble vitamin. The form of vitamin K present in foods is phytomenadione (vitamin K1). The substances synthesised by bacteria in our digestive system are known as menaquinones (vitamin K2). Vitamin K is essential for normal blood clotting. It is an essential co-factor for the liver to synthesise proteins involved in the regulation of blood clotting.
These are called prothrombin factors. The actual letter ‘K’ stands for the Danish word ‘koagulation’ meaning coagulation or clotting.Vitamin K is involved in the synthesis of a bone protein called osteocalcin, to its active form. Osteocalcin controls the function of calcium in bone turnover and mineralisation. Without vitamin K the bones produce an abnormal protein that is not compatible with other minerals that help form bones.
WHY YOU MAY NEED VITAMIN K
High cholesterol – early research suggests that vitamin K2 may reduce serum cholesterol in patients with elevated cholesterol levels. Osteoporosis – evidence suggests that vitamin K deficiency may contribute to osteoporosis. Studies have shown that patients taking anticoagulants, which are vitamin K antagonists are at increased risk of osteoporosis.
HOW MUCH DO YOU NEED?
Recommended Daily Intake (RDI) - An Australian RDI has not been established. Overseas: 1 mcg/kg of body weight is recommended Doses used in clinical trials Osteoporosis: up to 45 mg daily.
SYMPTOMS OF DEFICIENCY
<Haemorrhaging (bleeding) disease is a vitamin K deficiency disease characterised by excessive bleeding. Vitamin K can help regulate clotting. Vitamin K can also reduce excessive bleeding induced by certain medications eg salicylates and warfarin. Deficiency symptoms may include bone abnormalities, hip fracture, easy bruising, haemorrhaging, gastrointestinal bleeding, increased clotting time and nose bleeds. Food sources The best dietary sources of vitamin K include leafy green vegetables, broccoli, brussel sprouts, kale, soybean oil, kelp, meat, liver milk and eggs.
Vitamin E reduces the absorption of vitamin K. Large doses of vitamin E greater than 800 IU daily can increase the risk of bleeding in people who are taking warfarin, other anticoagulants or have low vitamin K intakes. Excessive intake of vitamin A (hyper-vitaminosis) can lead to a deficiency in clotting factor ‘thrombin’ in the blood causing increased bleeding time. Vitamin K can correct the problem.