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(HealthNewsDigest.com) – Vitamin K, discovered in mid 1930s, got its letter designation from the German word koagulation because of the vitamin’s first-known role in blood clotting. Blood remains a liquid in your body, even though it is loaded with all sorts of solid material – red and white blood cells, proteins, vitamins, minerals and fat. But it also can become a solid within seconds when a blood vessel breaks. The ability of blood to clot is dependent on vitamin K. If your body is short on K, your blood clots very slowly which could be life threatening.
Vitamin K is found in your liver, brain, heart, pancreas and bone, in addition to other body tissues. Very small amounts circulate in the blood and the vitamin is rapidly used or excreted from the body. Unlike other fat-soluble vitamins that can be stored in the body in large amounts, there is little storage for vitamin K. That is both good and bad. Good in that it is hard to get too much vitamin K and overdoses are rare. Bad in that you need a continuous supply to meet your body’s needs.
Most of our vitamin K comes from food. Green leafy vegetables and broccoli are particularly rich sources as are soybeans, soybean oil and canola oil. There are smaller amounts in meat, dairy foods and eggs. Very few foods, like breakfast cereals, are fortified with vitamin K, but some meal replacement shakes and bars have added K. What is unique about this vitamin is that it can be made in the body by the friendly bacteria in your gut. Though the amount of vitamin K you get through this route is unclear, most experts believe that at least some of the body’s requirement is met this way.
Experts estimate that most diets provide adequate amounts and both deficiencies and overdoses of vitamin K are rare. For this reason, few people have their vitamin K status routinely assessed unless they have a bleeding disorder or are taking anticoagulant drugs such as warfarin (Coumadin). These drugs antagonize the activity of vitamin K and seriously reduce vitamin K-dependent blood clotting factors.
Many who take anticoagulant drugs feels they need to avoid all foods containing vitamin K. This isn’t true. People taking warfarin need to maintain a consistent intake of vitamin K. Significantly lowering your vitamin K intake could increase the effect of warfarin, while increases in the vitamin may decrease the effect of the drug. The recommended daily Adequate Intake (AI) of vitamin K is 120 micrograms (mcg) for men and 90 micrograms for women.
A half cup of cooked kale has 531 mcg of vitamin K. The same amount of cooked spinach has 444 mcg, collards 418 mcg, swiss chard 287 mcg, and mustard green 210 mcg. This is why green leafy vegetables should be eaten less often and in smaller amounts. But at the other end of the scale a cup of Romaine lettuce has 57 mcg, a cup of iceberg lettuce has 14 mcg, a cup of avocado has 35 mcg, a half cup of cooked peas 21 mcg, a large egg 4 mcg, and a 3 ounce serving of salmon less than 1 mcg. As with all things, dose counts.
There is little need for a vitamin K supplement though the vitamin is often included in many daily vitamin and mineral brands. There are a few instances, however, where extra vitamin K is needed. Newborn babies are recommended to receive a one-time dose of vitamin K after birth because placental transport of this nutrient is poor and breast milk is low in K. People who deal with GI disorders such as cystic fibrosis, celiac disease and ulcerative colitis may not absorb vitamin K properly. The same goes for patients who have had bariatric weight reduction surgery.
Research is also focusing on two areas where vitamin K may play a role – bone health and heart disease. Vitamin K is a cofactor in osteocalcin, one of the main proteins found in bone. Some, but not all studies, have linked higher intakes of vitamin K with better bone mineral density and lower hip fracture. Vessel elasticity is important in maintaining heart health. Calcification of vessels is a risk factor for heart disease. Again, a vitamin K-dependent protein may play a role in the prevention of vessel stiffening. Though at this time, vitamin K’s role in heart disease prevention is still unclear, many findings show it may have a positive effect at reducing risk.
© NH Nutrition Consultants, Inc.
Jo-Ann Heslin, MA, RD, CDN is a registered dietitian and the author of 30 books. Available as eBooks from iTunes and Kindle/Amazon:
Diabetes Counter – the most up-to-date information on managing diabetes
Calorie Counter – a weight loss guide that won’t let you down
Protein Counter – put the latest protein recommendations to work for you
Healthy Wholefoods Counter – planet-friendly eating made easy
Complete Food Counter – food counts and nutrition information at your fingertips
Fat and Cholesterol Counter – newest approach to heart-healthy eating
Available in print from Gallery Books:
Most Complete Food Counter, 3rd Ed.
Your Complete Food Counter App: http://itunes.apple.com/us/app/your-complete-food-counter/id444558777?mt=8
For more information on Jo-Ann and her books, go to: www.TheNutritionExperts.com.
Most Complete Food Counter, 3rd Ed.
Your Complete Food Counter App: http://itunes.apple.com/us/app/your-complete-food-counter/id444558777?mt=8
For more information on Jo-Ann and her books, go to: www.TheNutritionExperts.com.