|SHEA, M. KYLA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|BOOTH, SARAH - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 10/1/2014
Publication Date: 11/28/2014
Citation: Shea, M., Booth, S.L. 2014. Vitamin K’s role in age-related bone loss: A critical review. In: Holick, M.F., Nieves, J.W. Nutrition and Bone Health. 2nd edition. New York, NY: Springer New York. p. 471-486. https://doi.org/10.1007/978-1-4939-2001-3_29.
Technical Abstract: The protective role of vitamin K in age-related bone loss continues to be controversial. The results of observational analyses are inconsistent with respect to associations between vitamin K status and bone, which arguably may be related to the limitations of observational study designs and analytical methodologies employed to measure vitamin K status. Well-designed randomized trials to test the effect of vitamin K on bone-loss without the bias of observational studies have been designed and completed. The majority of these trials do not support a protective effect of phylloquinone against age-related bone loss, especially when vitamin D and calcium status are adequate. The single randomized clinical trial that included fracture as an outcome had suggestive findings. However, it is unlikely that phylloquinone supplementation trials will be conducted that have a primary outcome of hip fracture given the prohibitively large sample size required and the lack of ancillary supporting evidence such as changes in bone turnover markers, bone mineral density and/or bone geometry. Although a number of the initial studies of menaquinone-4 demonstrated a benefit of therapeutic dose on bone loss, the results of the largest and longest menaquinone-4 trial to date overall did not find any benefit on vertebral fracture, except in women with advanced osteoporosis. Consistent evidence is lacking to support a protective effect of menaquinone-7 on bone loss as well. While the longest trial of menaquinone-7 supplementation reported a beneficial effect on femoral neck bone loss, confirmation in multiple clinical trials is needed.