What does vitamin k do?
Vitamin K is needed for proper bone formation and blood clotting. In both cases, vitamin K does this by helping the body transport calcium. Vitamin K is used by doctors when treating an overdose of the drug warfarin. Also, doctors prescribe vitamin K to prevent excessive bleeding in people taking warfarin but requiring surgery.
There is preliminary evidence that vitamin K2 (menadione), not vitamin K1 (phylloquinone; phytonadione), may improve a group of blood disorders known as myelodysplastic syndromes (MDS).1 These syndromes carry a significantly increased risk of progression to acute myeloid leukemia. Large-scale trials of vitamin K2 for MDS are needed to confirm these promising early results.
Leafy green vegetables, such as spinach, kale, collards, and broccoli, are the best sources of vitamin K. The greener the plant, the higher the vitamin K content.2 Other significant dietary sources of vitamin K include soybean oil, olive oil, cottonseed oil, and canola oil.3
Vitamin K has been used in connection with the following conditions (refer to the individual health concern for complete information):
Who is likely to be deficient of vitamin k?
A vitamin K deficiency, which causes uncontrolled bleeding, is rare, except in people with certain malabsorption diseases. However, there are reports of severe vitamin K deficiency developing in hospitalized patients who had poor food intake and were receiving antibiotics.4 All newborn infants receive vitamin K to prevent deficiencies that sometimes develop in breast-fed infants.
How much vitamin k is usually taken?
The recommended dietary allowance for vitamin K is about 1 mcg per 2.2 pounds of body weight per day or about 65 to 80 mcg per day for most adults.5 This level of intake may be achieved by consuming adequate amounts of leafy green vegetables. However, studies have shown that many men and women aged 18 to 44 years ingest less than the recommended amount of vitamin K.6 7
Are there any side effects or interactions with vitamin k?
Allergic reactions to vitamin K injections have been reported on rare occasions.8
Vitamin K facilitates the effects of calcium in building bone and proper blood clotting.
Are there any drug interactions?