"Hip" to Get Enough Vitamin K
By Rosalie Marion
February 26, 2003
Low dietary vitamin K intake has
been associated with an increased risk of hip fracture in men and women. But
until recently, little has been known about the association between dietary
vitamin K intake and bone mineral density (BMD).
Now scientists funded by the Agricultural
Research Service have reported findings which suggest that low dietary
vitamin K intake is associated with low BMD in women, though not in men. The
lead researcher, Sarah L. Booth, is director of the
Research Program at the Jean Mayer
USDA Human Nutrition Research Center on Aging at Tufts University in
Boston, Mass. She reported the findings in the February issue of The American Journal of Clinical Nutrition.
ARS is the U.S. Department of Agriculture's
chief scientific research agency.
BMD was measured at the hip and spine in 2,591 men and women, aged 29 to 86
years old, who participated in the
Study 1996-2000. Dietary and supplemental intakes of vitamin K were
assessed with the use of a food-frequency questionnaire.
Women with the lowest vitamin K intakes had significantly lower mean BMD at
the femoral neck and spine than did those with the highest intakes of the
vitamin. The data contribute to an expanding body of research that supports a
probable role of dietary vitamin K in reducing age-related bone loss, though
more studies are required.
Vitamin K helps certain proteins bind calcium and is required for proper
bone mineralization. The study results provide further evidence that a healthy
diet containing adequate vitamin K may help to assure adequate bone density and
protect against osteoporosis and hip fractures in postmenopausal women. The
current recommendation for vitamin K is 90 micrograms (mcgs) a day for women
and 120 mcgs for men. Green leafy vegetables and vegetable-derived oils and
spreads are good sources of fat-soluble vitamin K.