Bleeding, Bruising and Vitamin K

Vitamin k is a fat soluble vitamin used in the production of several blood clotting factors by the liver, including prothrombin.

It is also involved in bone mineralization through its effect on three proteins in bone; and cell signalling through its effect on another protein in the nervous system, heart, lungs, stomach, kidneys, and cartilage.

There are two forms - one synthesized by plants (phylloquinone), known as vitamin k1. The others, synthesized by bacteria, known collectively as vitamin k2.

It is stored in the liver and spleen, but not in large quantities. Dietary sources include spinach, cauliflower, cabbage, and liver, and some vegetable oils like soybean, cottonseed, canola, and olive (hydrogenation reduces absorption and bioavailability however).

vitamin k is a fat soluble vitamin Being a fat soluble vitamin, it can only be absorbed with bile salts and fat, so those taking diet pills or supplements inhibiting fat absorption, may need to assess their body's ability to absorb this vitamin whilst on them.

Others at risk of deficiency are those with liver damage and those taking warfarin. People taking warfarin are generally advised, as indicated on the Linus Pauling website, to take the recommended Adequate Intake (AI) of 90-120 mcg of vitamin k daily. The AI for adult males is 120 mcg/day, and for adult females its 90 mcg/day.

The Linus Pauling Institute further recommend taking a multi vitamin supplement (which usually contains 10 to 25 mcg) and eating 1 cup of dark green leafy vegetables daily. This is to supply enough k vitamins for the proteins in bone.

If you are taking antibiotics, your bowel flora may be affected, which may affect vitamin k formation. Either take a good acidophilus supplement, or increase dietary k vitamin consumption.

Symptoms of vitamin k deficiency include bruising and bleeding (nosebleed, bleeding gums, blood in the urine or stools, extremely heavy menstrual bleeding).

For detailed information on the role of vitamin k in blood clotting, click here.