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Vitamin K is best known for its role in helping blood clot properly, and in preventing excessive bleeding. It also plays an important role in bone health.
Vitamin K protects the body against the following.
Vitamin K also helps in the following ways.
Foods that contain a significant amount of vitamin K include chlorophyll, green tea, turnip greens, broccoli, spinach, cabbage, asparagus, and dark green lettuce.
Freezing foods may destroy vitamin K, but heating does not affect it.
How to Take It
The recommended dietary allowance (RDA) for vitamin K is 80 mcg for men, and 65 mcg for women. To help prevent and treat disease, increase the amount of dark green leafy vegetables you eat, and supplement your diet with up to 500 mcg of vitamin K each day.
As with all medications and supplements, check with a health care provider before giving vitamin K supplements to a child.
Vitamin K counteracts the effects of the blood-thinning medication warfarin, rendering the medication ineffective. When taking this medication, do not take vitamin K supplements and avoid foods with high quantities of this nutrient.
Antibiotics, particularly a class known as cephalosporins, reduce the absorption of vitamin K. This is a particular problem for people who already have low levels of vitamin K or are at risk for deficiency (such as those who are malnourished, elderly, or taking warfarin).
The cholesterol-lowering medication cholestyramine may also reduce the absorption of vitamin K.
Taking anticonvulsants (such as phenytoin) during pregnancy or while breastfeeding may deplete vitamin K in newborns; consult your obstetrician and/or pediatrician for advice on nutrient replacement therapy.
Bendich A, Decklebaum R. Preventive Nutrition: The Comprehensive Guide for Health Professionals. Totowa, NJ: Humana Press; 1997.
Breen GA, St. Peter WL. Hypoprothrombinemia associated with cefmetazole. Ann Pharmacother. 1997;31(2):180-184.
Drug Facts and Comparisons 1999. St. Louis, Mo: Facts and Comparisons; 1998: 270–272.
Craciun AM, Wolf J, Knapen MH, Brouns F, Vermeer C. Improved bone metabolism in female elite athletes after vitamin K supplementation. Int J Sports Med. 1998;19:479–484.
Feskanich D, Weber P, Willett WC, Rockett H, Booth SL, Colditz GA. Vitamin K intake and hip fractures in women: a prospective study. Am J Clin Nutr. 1999;69:74–79.
Hathcock, JN. Metabolic mechanisms of drug-nutrient interactions. Fed Proc. 1985;44(1):124-129.
Huilgol VR, Markus SL, Vakil NB. Antibiotic-induced iatrogenic hemobilia. Am J Gastroenterol. 1997;92(4):706-707.
Jatoi A, Lennon C, O'Brien M, Booth SL, Sadowski J, Mason JB. Protein-calorie malnutrition does not predict subtle vitamin K depletion in hospitalized patients. Euro J Clin Nutri. 1998; 52:934–937.
Jie KG, Bots ML, Vermeer C, Witteman JC, Grobbee DE. Vitamin K status and bone mass in women with and without aortic atherosclerosis: a population-based study. Calcif Tissue Int. 1996;59:352–356.
Knodel LC, Talbert RL. Adverse effects of hypolipidaemic drugs. Med Toxicol. 1987;2(1):10-32.
Kohlmeier M, Saupe J, Shearer MJ, Schaefer K, Asmus G. Bone health of adult hemodialysis patients is related to vitamin K status. Kidney Int. 1997;51:1218–1221.
Krummel D, Kris-Etherton P. Nutrition in Women's Health. Gaithersburg, Md: Aspen Publishers; 1996:434–435.
Lubetsky A, Dekel-Stern E, Chetrit A, Lubin F, Halkin H. Vitamin K intake and sensitivity to warfarin in patients consuming regular diets. Thromb Haemost. 1999;8:396–399.
Matsui MS, Rozovski, SJ. Drug-nutrient interaction. Clin Ther. 1982;4(6):423-440.
Murray M. Encyclopedia of Nutritional Supplements. Rocklin, Calif: Prima Publishing; 1996:54–58.
Novel form of vitamin K may stop liver cancer cell growth. Oncology. 1998;12:1541.
Reavley N. Vitamins, Etc. Melbourne, Australia: Bookman Press; 1998
Shils ME, Olson JA, Shike M, Ross CA, eds. Modern Nutrition in Health and Disease. 9th ed. New York, NY: Lippincott, Williams & Wilkins; 1998.
Suzuki K, Fukushima T, Meguro K, et al. Intracranial hemorrhage in an infant owing to vitamin K deficiency despite prophylaxis. Childs Nerv Syst. 1999;15(6-7):292-294.
Tamatani M, Morimoto S, Nakajima M, et al. Decreased circulating levels of vitamin K and 25-hydroxyvitamin D in osteopenic elderly men. Metabolism. 1998;47:195–199.
Which vitamin K preparation for the newborn? Drug Ther Bull. March 1998;36:17–19.
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