Vitamin K ( Antihaemorrhagic Factor )

It is a fat-soluble vitamin and it is also called as antihaemorrhagic factor.

Dam discovered this vitamin later than studying haemorrhagic disease in chickens in 1930 and 1933.

Two naturally happening vitamins K are vitamin K1 (phyllouinone, phytonadione) and vitamin K2 (flavinoquinone, farnoquinone Activity is apparently connected to the existence of methyl group at 2 positions in the quinonoid ring. Synthetic vitamin K is known as vitamin K2 (commercially menadione).

It is fat-soluble; heat constant and can stand cooking. Vitamin K1 is yellow viscid oil, but vitamin K2 is a yellow, crystalline solid. The K vitamins are readily damaged by light, alkali and alcohol.

Sources of vitamin K

Vegetable sources are rich, such as cabbage, spinach, alfalfa, tomato, and soyabin, etc. It is absorbed from the intestine with the help of bile salts. Most putrefied animals and plants include significant amount of vitamin K. It has also been formed synthetically. Under normal conditions, usual intestinal bacteria synthesize adequate amounts. Extreme amount of vitamin A administration in certain species produces obstruction with bacterial synthesis of vitamin K in the intestine producing prothrombinaemia and haemorrhagic manifestations. Cow's milk is a very better source of vitamin K than human milk.

Functions of vitamin K:

It helps to keep the formation of normal prothrombin and issue VII in the blood and thus take part in normal coagulation. It has been postulating that vitamin K behave as the prosthetic group to an apoenzyme to create a holoenzyme, which is concerned in the clotting, reactions. Prothrombin and issue VII are created in the liver. The principal overall effect of vitamin K is to shorten the prothrombin time. It is also called that vitaminK1 is a necessary component of phosphorylation in both the processes of photosynthesis in green plants and animal tissues, as a cofactor essential in oxidative phosphorylation.

Bile salts are needed for the absorption of vitamin K. In jaundice and in certain diseases of liver, when the bile secretion is defective, vitamin K fails to be absorbed resultant haemorrhages. Hepatic diseases also produce hypoprothrombinaemia, which is corrected by vitamin K administration. The haemorrhagic disease in the newborn is believed to be due to short of Vitamin K, since vitamin K deficiency in the newborn is due to lack of bacteria in their gut. An important therapeutic use of vitamin K is as an antidote to the anticoagulant drugs such as dicumarol.

Studies have exposed that the vitamin K1 and K2 are also preventive next to cancer. Vitamin K is one of the most significant nutritional requirements for improving bone density. It serves as the biological "glue" that helps to bind the calcium into the bone matrix. Vitamin K helps to prevent hardening of the arteries, which is a common issue in coronary artery disease and heart failure.

The pancreases, which make insulin, have the second uppermost amount of vitamin K in the body. Japanese researchers found that vitamin K deficiency can have effects like to diabetes.

Deficiency signs of vitamin K

Imperfect blood coagulation and haemorrhages. In vitamin K deficiency, the prothrombin content of blood is decreased and the blood clotting time is considerably prolonged. Deficiency of vitamin K may lead to Alzheimer's disease.

Who needs vitamin K

If a patient has a history of osteoporosis or coronary heart disease, he may require supplements of vitamin K. Chron's disease, ulcerative colitis, celiac disease and other conditions that interfere with nutrient absorption also occurs due to Liver disease that interferes with vitamin K storage Taking drugs such as broad-spectrum antibiotics, and aspirin also produces deficiency of vitamin K.

Who does not needs vitamin K

Pregnant and nursing mothers should avoid vitamin K supplements intakes higher than the RDA (65 mcg) unless specifically recommended and monitored by their physician. Those who have experienced stroke, cardiac arrest, and those prone to blood clotting should not take vitamin K without consulting their physician.

Daily requirement:

Normal mixed diet supplies this vitamin in adequate amount. In the treatment of haemorrhagic diseases created as a result of vitamin K deficiency, 5 mgm is given orally or by injection. It is believed that in adults, the bacteria in the gut synthesize quite a superior amount of vitamin K.

Pediatric:

- Infant's birth to 6 months: 2mcg

- Infants 7 to 12 months: 2.5 mcg

- Children 1 to 3 years: 30mcg

- Children 4 to 8 years: 55 mcg

- Children 9 to 13 years: 60 mcg

- Adolescence 14 to 18 years: 75 mcg

- A single injection of vitamin K is also given at birth.

Adults:

- Males 19 years and older: 120 mcg

- Females 19 years and older: 90 mcg

- Pregnant and breastfeeding females 14 to 18 years: 75 mcg

- Pregnant and breastfeeding females 19 years and older: 90 mcg