The K vitamins exist naturally as K 1 (phylloquinone) in green vegetables and K 2 (menaquinone) produced by intestinal bacteria and K 3 is synthetic menadione. When administered, vitamin K 3 is alkylated to one of the vitamin K 2 forms of menaquinone.
Vitamin K is also essential for bone formation and repair; it is necessary for the synthesis of osteocalcin, the protein in bone tissue on which calcium crystallizes. Consequently, it may help prevent osteoporosis.
Food Sources of Vitamin K
Vitamin K is found in leafy vegetables, cheese and liver. It is also found in asparagus, coffee, bacon and green tea.
Vitamin K is also made by the bacteria that line the gastrointestinal tract.
Functions of Vitamin K
Vitamin K is known as the clotting vitamin, because without it blood would not clot. Some studies indicate that it helps in maintaining strong bones in the elderly.
Vitamin K plays an important role in the intestines and aids in converting glucose into glycogen for storage in the liver, promoting healthy liver function.
The recommended daily intake for vitamin K is 80 micrograms for men and 65 for women. Because this vitamin is found in so many foods, especially green leafy vegetables and commonly used cooking oils, most adults get enough of it. According to a 1996 survey, though, a substantial number of Americans, particularly children and young adults, aren't getting the vitamin K they need.
What are the deficiency symptoms of vitamin K?
The intestine of newborn infants is sterile, therefore, vitamin K deficiency in infants is possible if lacking from the early diet. A deficiency of this vitamin in newborn babies results in hemorrhagic disease, as well as postoperative bleeding and hematuria while muscle hematomas and inter-cranial hemorrhages have been reported. A shortage of this vitamin may manifest itself in nosebleeds, internal hemorrhaging. Vitamin K deficiency can also occur after prolonged treatment with oral antibiotics. Individuals with vitamin K deficiency usually have an increased propensity to bruising and bleeding.
Overdosage signs of vitamin K
Infants may have brain damage and impaired liver function.
Large amounts of phylloquinone or menaquinones can be consumed over extended periods with no toxic effects.
Bile acid sequestrants (Cholestyramine, colestipol): decrease its absorption.
Coumarin anticoagulants (Warfarin): Its ability to work depends on the amount of this vitamin in the blood.Extra supplementation will alter the effect of these medications and the dose needed for treatment.
Antibiotics: decrease the amount of this nutrient that is normally made by decreasing the beneficial bacteria in the digestive tract.
Anticonvulsants (Barbiturates, phenytoin): increase the breakdown of vitamin K in the body resulting its deficiency.
How to Store the Vitamin K?
Heat and/or moisture may alter the vitamin. Refrigeration is recommended.
Vitamin K Deficiency