Vitamin K

Vitamin K is not just one substance but is actually a group of substances identified as naphthoquinones. Most of the human’s sources of vitamin K come from plant sources, particularly the green leafy vegetables.

Special Precautions of Vitamin K

Although allergic reaction from supplementation is possible, there is no known toxicity associated with high doses of the phylloquinone (vitamin K1) or menaquinone (vitamin K2) forms of vitamin K and therefore no tolerable upper intake level (UL) has been set. Blood clotting (coagulation) studies in humans using 45 mg per day of vitamin K2 (as MK4)[25] and even up to 135 mg/day (45 mg three times daily) of K2 (as MK4),[50] showed no increase in blood clot risk. Even doses in rats as high as 250 mg/kg body weight did not alter the tendency for blood-clot formation to occur. However, a synthetic form of vitamin K, vitamin K3 (menadione), is demonstrably toxic. In fact, the FDA has banned this synthetic form of the vitamin from over-the-counter supplements because large doses have been shown to cause allergic reactions, hemolytic anemia, and cytotoxicity in liver cells.[1] [edit]Drug interactions

Phylloquinone (K1)or menaquinone (K2) are capable of blocking the blood thinning action of anticoagulants like warfarin, which work by interfering with the action of vitamin K. They also reverse the tendency of these drugs to cause arterial calcification in the long term.

The benefits of Vitamin K are

• Vitamin K is best known in its ability to promote blood clotting. In fact, the letter “K” comes from the German term, koagulation.
• Vitamin K has more functions other than clotting; vitamin K is also beneficial in protecting the bones from fractures and in helping women in their menopausal stage from having unhealthy bones. The link between bone health and vitamin K has been researched extensively. Primary to this is the ability of vitamin K, in its menaquinone form, to impede the formation of osteoclasts. Osteoclasts are responsible for removing the minerals in the bone for proper body functioning. While these minerals are important in the body, we do not want too much of the osteoclastic activity as it can result to bone demineralization. Therefore, if vitamin K is increased, there will be less demineralization of bones, less chances of getting fractures.
• Calcium belongs in our bones, not in our blood. When our vitamin K2 levels are low, calcium collects in our blood and can lead to calcification in our arteries.

Males require 120 micrograms of vitamin K, while females only need 90 micrograms daily. The excellent source of vitamin K is boiled kale and boiled spinach, which can provide over 1000 percent of the nutrients daily value per 1 cup of the vegetable.