Vitamin K deficiency isn't common, except among people taking certain medications or a small percentage of newborns. The majority of necessary vitamin K is manufactured in the intestines. Because vitamin K is found in many foods, including greens and leafy green vegetables as well as some vegetable oils, most people get adequate amounts each day. Vitamin K in the body helps produce proteins that form clotting factors and also appear to aid in building bone. When people do develop vitamin K deficiency, symptoms can range from mild to severe.
Bleeding
Seven different proteins depend on vitamin K for their synthesis. These include prothrombin, also called Factor II; Factors VII, IX and X; and protein C, S and Z. Without these proteins, blood doesn't clot properly at the site of an injury. Lack of blood clotting factors due to vitamin K deficiency can cause either internal or external bleeding. Signs of internal bleeding include bruising, especially if no injury is present; blood in the bowel movement, which can include the passage of dark, sticky, tarry stools; or blood in the urine. External signs of bleeding can include cuts that bleed longer than normal, bleeding gums or frequent bloody noses. Heavier-than-normal menstrual periods can also indicate a vitamin K deficiency. Medications that can interfere with vitamin K synthesis of clotting proteins include warfarin, an anticoagulant medication that decreases blood clotting, and anti-seizure medications.
Brain Hemorrhage
In newborns, a rare type of vitamin K deficiency called hemorrhagic disease of the newborn occurs in approximately 2.5 to 17 newborns per thousand births, reports Ted Tulchinsky, M.D., of the Hebrew University in Jerusalem. Because bacteria in the gut synthesize vitamin K and newborns don't have bacteria in the gut, they don't produce vitamin K immediately. While HDN can cause diffuse bleeding into the gastrointestinal tract, nose, scalp and urinary tract, it can also cause hemorrhage into the brain that leads to brain damage or death. In Japan, 82 percent of infants with HDN developed intracranial or intraventricular hemorrhage, bleeding into the ventricles of the brain. The American Academy of Pediatricians advises that all newborns receive vitamin K shortly after birth.
Low Vitamin K Density
Vitamin K helps synthesize three proteins necessary for bone formation: osteocalcin; matrix Gla protein, also called MGP; and protein S. A lack of vitamin K may reduce bone mineral density. Researchers at Wonkwang University in Korea reported on vitamin K intake and bone mineral density in young women in the December 2010 issue of "Nutritional Research and Practice." The study found a correlation between vitamin K intake and bone mineral density, with women who had a vitamin K deficiency more likely to have low bone mineral density levels.
Bone Fractures
Anticoagulants such as warfarin interfere with the actions of vitamin K in the body. People who take anticoagulants long-term may have an increased risk of bone fractures. A Mayo Clinic study reported in the August 1999 "Archives of Internal Medicine" found an increased risk of vertebral and rib fractures in women who took anticoagulants. The risk increased with the amount of time the women took anticoagulants.
References
- Colorado State University: Vitamin K
- Braun School of Public Health, Hebrew University-Hadassah, Jerusalem; Vitamin K and Hemorrhagic Disease of the Newborn; Ted Tuchinsky
- "Nutrition Research and Practice"; Relationship Between Vitamin K Status, Bone Mineral Density, and hs-CRP in Young Korean Women; M. Kim, et al.; December 2010
- Linus Pauling Institute, Oregon State University; Vitamin K; Jane Higdon, Ph.D; May 2004
- "Archives of Internal Medicine"; Long-Term Use of Oral Anticoagulants and the Risk of Fracture; P. Caraballo, et al.; August 1999
Member Comments