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Vitamin K - Food Sources and Deficiency Symptoms
Vitamin K is a fat-soluble vitamin, which can be produced in the intestines. There are two naturally occurring forms of vitamin K. i.e. K1, also called phylloquinone, is found in plants and vitamin K2, also called menaquinone, which can be synthesized by many bacteria. Vitamin K3, menadione, is a synthetic form of this vitamin which is manmade.
Vitamin K denotes a group of 2-methilo-naphthoquinone derivatives. They are human vitamins , lipophilic and therefore hydrophobic. Viotamin K is needed for the synthesis of several proteins that mediate both coagulation and anticoagulation. Vitamin K deficiency is manifest as a tendency to bleed excessively. Indeed, many commercially-available rodent poisons are compounds that interfere with vitamin K and kill by inducing lethal hemorrhage.
A vitamin K deficiency is fairly uncommon in healthy adults, because bacteria in the intestines synthesize the vitamin. It may however occur in individuals that take medicinal vitamin K antagonists.
Sources of Vitamin K:-
The important sources of vitamin K are as:-
- It is mainly found in cabbage, cauliflower, spinach, cereals, soybeans, and other vegetables. Vitamin K is also made by the bacteria that line the gastrointestinal tract.
- Vitamin K is found in a number of foods, including leafy greens. The chief source of vitamin K is synthesis by bacteria in the large intestine , and in most cases, absence of dietary vitamin K is not at all deleterious.
- Vitamin K is a fat-soluble vitamin and both dietary and microbial vitamin K are absorbed into intestinal lymph along with other lipids. The fetus obtains vitamin K from its mother by transplacental transfer.
Deficiency of Vitamin K:
Deficiency in vitamin K and resulting hemorrhagic disease can result from several situations:
- One form of vitamin K deficiency is hemorrhagic disease of the newborn, characterized by a tendency to bleed.
- Poisoning with vitamin K antagonists : In severe condition, a vitamin K deficiency can leads to death by bleeding.
- Liver disease : Vitamin K, as a fat-soluble vitamin, requires proper lipid absorption for its own absorption. Liver disease that results in decreased bile salt synthesis leads to impaired vitamin K absorption and deficiency.
- Intestinal disease : This disease result in lipid malabsorption in the small intestine can lead to defects in absorption of vitamin K, as discussed above for liver.
- Disorders that interfere with fat absorption can reduce the absorption of vitamin K and cause vitamin K deficiency. Taking large amounts of mineral oil may reduce the absorption of vitamin K. A vitamin K injection is usually given to newborns to protect them from this disease. Breastfed infants who have not received this injection at birth are especially susceptible to vitamin K deficiency.
Functions of Vitamin-K:
- Vitamin K protects the heart: The heart attack is associated with calcification of the aorta, especially in young men. It is mainly due to deficiency of vitamin K.
- Vitamin K works through an amino acid called "Gla," which stands for gamma-carboxyglutamic acid. Gla is part of a certain kind of protein that controls calcium.
- Vitamin K provides strength to the bones and muscles.
- Vitamin K performs a feat on the proteins called "carboxylation." Carboxylation gives the proteins claws so they can hold onto calcium.
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