Vitamin K.
Vitamin K is a fat-soluble coenzyme. Although it is produced within  the body, it is still considered essential. Gut flora are bacteria which are normally established in the intestine. These bacteria synthesize menaquinone, an active form of vitamin K. However, the produced quantities are not enough to meet the total requirements for optimum health.
The primary function of vitamin K is to promote the synthesis of prothrombin and other factors which are necessary for coagulation. This is a biochemical procedure that prevents excessive bleeding by contributing to the formation of blood clot.
Quite often, oral anticoagulants, such as warfarin or aspirin, are prescribed for people who are at high risk for clot formation in the blood vessels. Coagulation is responsible for angina, coronary heart disease, stroke and deep venous thrombosis. Anticoagulants restrain the action of vitamin K. The latest, after its usage, is recycled in the body. Warfarin medication causes deficiency-like state by interfering with this process.
Another cause that can hinder coagulation is any severe liver disorder that can lead to low concentrations of vitamin K-dependent clotting factors within the blood stream.
Excessive amounts of vitamin A or alpha-tocopherol can counteract the blood clotting effects of vitamin K, as well.
Vitamin K plays a key role in proper use of calcium and consequently, protects bones by helping in adequate mineralization, promoting good formation and improving density. Vitamin K can prevent osteoporosis in postmenstrual women and easy-happening bone fractures in elderly people. Vitamin K can also protect from aortic calcification, a condition that leads to atherosclerosis and cardiovascular disease, in general.
Sources of vitamin K.
Although vitamin K is fat-soluble, it is hardly stored within the body. Thus, a constant dietary intake is necessary, in order to prevent any depletion of the vitamin. The good news is that vitamin K is highly contained in a wide range of foods and can be readily obtained from them. It is remarkable that a single cup of spinach contains nearly 120mcg which is almost twice the recommended dietary allowance (RDA).
Vitamin K is found in leafy vegetables, such as Brussels sprout, cabbage, kale, parsley, endive, spring onions, watercress, cauliflower, broccoli, spinach and lettuce. It is also present in oils derived from olives, canola, soybeans and cottonseeds. Hydrogenated vegetable oils are not good sources of vitamin K, though.
Other foods containing vitamin K include avocado, kiwifruit, pistachio nuts, asparagus, dairy products, eggs, organic meat and liver.
Deficiency and toxicity of vitamin K.
Vitamin K deficiency is very rare, in healthy people, and occurs, when there is an inability of the body to absorb the vitamin within the intestinal tract due to fat malabsorption. Deficiency in vitamin K can lead to poor formation of blood clot which, in turn, results in excessive and prolonged menstrual bleeding, unexplained nosebleeds, hemorrhagic gums, macroscopic hematuria, black stools and intracranial hemorrhage. Deficiency may occur after prolonged antibiotic courses as well.
Vitamin K toxicity is extremely rare, since the nutrient is not stored in the body and cannot accumulate to excessive amounts.
Recommendations for vitamin K.
For adults, the vitamin K recommended dietary allowance (RDA) ranges from 60-80mcg/day, depending on the individual's weight.
It is important for people taking anticoagulants, such as aspirin or warfarin, to know that vitamin K may reduce the effectiveness of these medications. However, a reasonable dietary intake that meets the elemental requirements (RDA) is allowed and recommended.
Postmenstrual women and males beyond the age of seventy need twice the vitamin K RDA, in order to prevent osteoporosis and easy-happening bone fractures.
In general, adequate amounts of vitamin K can easily be obtained from foods. However, in elderly, a daily supplementation of 100mcg may be needed. The following  button will help you to find such vitamin K supplements online. |
