Vitamin K is found in nature in two forms - 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.
Sources of Vitamin K
Vitamin K is produced by bacterial flora, and is easy to acquire in the diet. Vitamin K is found in leafy green vegetables such as spinach and lettuce; Brassica vegetables such as kale, cabbage, cauliflower, broccoli, and Brussels sprouts; wheat bran; cereals; some fruits; and other dairy products; soybeans; and other soy products. Two tablespoons of parsley contains 153% of the recommended daily amount of Vitamin K.
Vitamin K is required for
Vitamin K is used in the body to control blood clotting and is essential for synthesizing the liver protein that controls the clotting. It is involved in creating the important prothrombin, which is the precursor to thrombin - a very important factor in blood clotting. It is also involved in bone formation and repair. In the intestines it also assists in converting glucose to glycogen, this can then be stored in the liver. There are some indications that Vitamin K may decrease the incidence or severity of osteoporosis and slow bone loss.
Role in disease
Vitamin K-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct obstruction), by therapeutic or accidental intake of vitamin K-antagonists or, very rarely, by nutritional vitamin K-deficiency. As a result of the acquired vitamin K-deficiency, Gla-residues are not or incompletely formed and hence the Gla-proteins are inactive. Lack of control of the three processes mentioned above may lead to the following: risk of massive, uncontrolled internal bleeding, cartilage calcification and severe malformation of developing bone, or deposition of insoluble calcium salts in the arterial vessel walls.
Deficiency of vitamin K
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.
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Age Male Female Pregnancy Lactation
Birth to 6 months 2.0 mcg 2.0 mcg
7–12 months 2.5 mcg 2.5 mcg
1–3 years 30 mcg 30 mcg
4–8 years 55 mcg 55 mcg
9–13 years 60 mcg 60 mcg
14–18 years 75 mcg 75 mcg 75 mcg 75 mcg
19+ years 120 mcg 90 mcg 90 mcg 90 mcg
When more may be required
This nutrient can be destroyed by freezing and radiation as well as air pollution. Absorption may be decreased when rancid fats are present, as well as excessive refined sugar, antibiotics, high dosages of vitamin E, or calcium and mineral oils.
Enemy of vitamin K
When you are prone to bruising easily, or when pregnant you might be in need of more Vitamin K. But be careful not to take too much Vitamin K in the last stages of pregnancy, since it could be toxic for the baby.
Use on newborn babies
In some countries, injections of Vitamin K are routinely given to newborn babies. Vitamin K is used as prophylactic measure to prevent late-onset hemorrhagic disease (Hemorrhagic disease of the newborn is a coagulation disturbance in newborns due to vitamin K deficiency. As a consequence of vitamin K deficiency there is an impaired production of coagulation factors II, VII, IX and X by the liver.). However, HDN is a relatively rare problem, and many parents now choose for their babies not to have such an injection.
Vitamin K on Wikipedia
Vitamin K on NIH