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Bone Health and Osteoporosis: The Role of Vitamin K and Potential Antagonism by Anticoagulants
Author(s) -
Pearson Debra A.
Publication year - 2007
Publication title -
nutrition in clinical practice
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 71
eISSN - 1941-2452
pISSN - 0884-5336
DOI - 10.1177/0115426507022005517
Subject(s) - medicine , osteoporosis , bone remodeling , osteocalcin , vitamin d and neurology , anticoagulant , vitamin , bone mineral , clotting factor , intensive care medicine , surgery , biochemistry , chemistry , alkaline phosphatase , enzyme
Background: Vitamin K's effects extend beyond blood clotting to include a role in bone metabolism and potential protection against osteoporosis. Vitamin K is required for the γ‐carboxylation of osteocalcin. Likewise, this γ‐carboxylation also occurs in the liver for several coagulation proteins. This mechanism is interrupted by coumarin‐based anticoagulants in both the liver and bone. Methods: A thorough review of the literature on vitamin K, osteocalcin and their role in bone metabolism and osteoporosis, as well as the potential bone effects of anticoagulant therapy was conducted. Conclusions: Epidemiological studies and clinical trials consistently indicate that vitamin K has a positive effect on bone mineral density and decreases fracture risk. Typical dietary intakes of vitamin K are below the levels associated with better BMD and reduced fracture risk; thus issues of increasing dietary intakes, supplementation, and/or fortification arise. To effectively address these issues, large‐scale, intervention trials of vitamin K are needed. The effects of coumarin‐based anticoagulants on bone health are more ambiguous, with retrospective studies suggesting that long‐term therapy adversely affects vertebral BMD and fracture risk. Anticoagulants that do not affect vitamin K metabolism are now available and make clinical trials feasible to answer the question of whether coumarins adversely affect bone. The research suggests that at a minimum, clinicians should carefully assess anticoagulated patients for osteoporosis risk, monitor BMD, and refer them to dietitians for dietary and supplement advice on bone health. Further research is needed to make more efficacious decisions about vitamin K intake, anticoagulant therapy, and bone health.