Vitamin K - Benefits, Deficiency Symptoms And Food Sources
Vitamin K is a fat-soluble vitamin essential for the clotting of blood. If blood does not clot, a single pinprick can drain the entire body of all its blood. Vitamin K acts primarily in blood clotting, where its presence can make the difference between life and death. The 'K' is derived from the Danish word 'koagulation' meaning blood, clotting.
Vitamin K was discovered by Dr. Dam in 1935 as a factor that prevented severe haemorrhage in animals. The factor was named 'koagulationsvitamin' and subsequently 'vitamin K'. The vitamin was first isolated from alfalfa and Dr. Dam was awarded the Nobel Prize for his discovery.
Several forms of vitamin K have been identified, all of them belonging to a group of chemical compounds called quinones. Phylloquinone (vitamin K1) is the major form found in plant foods and was initially isolated from alfalfa by Dr. Dam. It is our dietary form of vitamin K. Menaquinone (vitamin K2) is synthesized by the bacteria in our intestinal tract. Vitamin K1 and K2 are natural, fat-soluble forms of the vitamin. menadione (vitamin K3) is a synthetic, watersoluble form of the vitamin, which is two to three times more potent than the natural vitamin. Being water-soluble, vitamin K3does not require the presence of bile for absorption.
Like other fat-soluble vitamins, vitamin K is absorbed along with fat in the presence of bile acids. Our body does not maintain large stores of vitamin K unlike other fat-soluble vitamins. Vitamin K is rapidly cleared from the body in urine. However, the small amount of vitamin K in the body is recycled and used again.
Vitamin K is fat-soluble, resistant to heat, but easily destroyed by acids, light and oxidizing agents.
Functions of vitamin K
Vitamin K has an important function in the clotting of blood. Several steps in the blood-clotting process depend on vitamin K. Recent research has also explored some role of vitamin K in bone development.
Role of vitamin K in blood clotting :- Normally, blood flows in our body without clotting. But when bleeding occurs because of injury, the blood clots and the bleeding is stopped. The clot is made of fibrin; a protein that gets deposited
in the form of fine threads to form a network.
The formation of fibrin is not a one-step process but a series of events, which requires a number of clotting factors. These clotting factors are proteins, which are synthesized by liver in an inactive form. The activation of four of these factors, including factor II, VII, IX and X, requires vitamin K.
Role of vitamin K in bone development :- Vitamin K also participates in the synthesis of bone proteins. Osteocalcin is a protein present in the bone, which binds calcium and is involved in the bone development. This protein is dependent on vitamin K; without vitamin K, it cannot bind, calcium.
Benefits of Vitamin K
Vitamin K will provide you with health rather than wealth, but there's no mistaking that it's loaded with benefits. Aside from its many already proven functions, researchers now believe that Vitamin K prevents osteoporosis, the disease that weakens the bones, a function that until now seemed primarily in calcium's hands. Specifically, vitamin k may help to:
Daily allowances of vitamin k
The minimum Recommended Dosage Allowance of Vitamin K are :-
Rich sources of vitamin K
Vitamin K is found in foods, including asparagus blackstrap molasses, cauliflower, cabbage, spinach, alfalfa, yoghurt, soya beans , and, to a lesser extent, in wheat and oats. Herbs that can supply vitamin K include alfalfa, green tea, kelp, nettle, oat straw, and shepherd's purse
Deficiency symptoms of Vitamin K
Primary vitamin K deficiency (deficiency due to inadequate intake) is rare. Even though our body stores a limited amount of vitamin K, a shortage of vitamin K is unlikely, since it is derived from both food and bacterial synthesis in our intestine. Green leafy vegetables are high in vitamin K, fruits and cereals are low, and meat and dairy products are intermediate in vitamin K content.
Excess of vitamin K deficiency results in impaired blood clotting; symptoms include easy bruising, nosebleeds, bleeding gums, blood in the urine and stools, or extremely heavy menstrual bleeding. Deficiency in infants may result in life-threatening bleeding, leading to haemorrhage.
Vitamin K deficiency may occur when the absorption of fat and related substances is abnormal, due to long-term antibiotic therapy which results in sterilization of the gut, when anticoagulant drugs have been used to prevent blood clotting, immediately after birth because bacteria are not present in the gastrointestinal tract, and severe liver disease.
Heamorrhagic disease in newborns :- Newborns may develop heamorrhagic diseases due to lack of vitamin K because:
Premature infants are more susceptible to vitamin K deficiency because of poor transfer of vitamin K through the placenta. Newborns are often given a single injection of vitamin K after birth to prevent deficiency.
Large amounts of vitamin A and E also interfere with the absorption and metabolism of vitamin K.
Vitamin K toxicity
There is no known toxicity associated with high doses of phylloquinone (vitamin K1), a natural form of vitamin K. However, when menadione (vitamin K), a synthetic form, is given in large doses, especially to infants and pregnant women, toxicity can occur. High doses of vitamin K can also reduce the effectiveness of anticoagulant drugs. Toxicity symptoms include jaundice, red blood cell haemolysis and brain damage.
(c) Health-care-clinic.org All rights reserved
Disclaimer: Health-care-clinic.org website is designed for educational purposes only. It is not intended to treat, diagnose, cure, or prevent any disease. Always take the advice of professional health care for specific medical advice, diagnoses, and treatment. We will not be liable for any complications, or other medical accidents arising from the use of any information on this web site. Please note that medical information is constantly changing. Therefore some information may be out of date.