Abstract:
The effect of the prolonged intake of dietary vitamin K2 (menaquinone-7, MK-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 μg MK-7/100 g diet) without or with supplemental MK-7 (containing 14.1 or 18.8 μg of MK-7 as total per 100 g diet) for 150 days. Feeding produced a significant elevation of MK-7 concentration in the serum of OVX rats. In this case, the femoral MK-4 content was significantly increased, but MK-7 was not detected in the femoral tissues, indicating degradation of MK-7. Serum γ-carboxylated osteocalcin concentration was significantly decreased by OVX. This decrease was significantly prevented by the feeding of the natto diets with supplemental MK-7 (18.8 μg/l00 g diets). OVX caused a significant decrease in femoral dry weight, femoral calcium content, and mineral density. These decreases were significantly prevented by feeding with diets containing natto with MK-7 (total, 18.8 μg/100 g diets). This study demonstrates that the prolonged intake of natto dietary including MK-7 has a preventive effect on bone loss induced by OVX. Dietary MK-7 may be useful in the prevention of osteoporosis.
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Received: June 18, 1999 / Accepted: Sept. 3, 1999
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Yamaguchi, M., Kakuda, H., Gao, Y. et al. Prolonged intake of fermented soybean (natto) diets containing vitamin K2 (menaquinone-7) prevents bone loss in ovariectomized rats. J Bone Miner Metab 18, 71–76 (2000). https://doi.org/10.1007/s007740050014
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DOI: https://doi.org/10.1007/s007740050014