Effect of vitamin K2 (menaquinone-7) in fermented soybean (natto) on bone loss in ovariectomized rats

J Bone Miner Metab. 1999;17(1):23-9. doi: 10.1007/s007740050059.

Abstract

The effect of dietary vitamin K2 (menaquinone-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing menaquinone-4 (MK-4; 12mg/100g diet) or menaquinone-7 (MK-7; 18.1mg/100g diet) for 24 days; MK-4 and MK-7 were equal in molar concentrations. This feeding caused a remarkable increase of MK-4 and MK-7 concentrations in the serum and femur of OVX rats. OVX-induced decrease in the femoral dry weight and femoral calcium content was prevented by the feeding of dietary MK-4 or NK-7. In separate experiments, OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 microg MK-7/100g diet) without or with added MK-7 (37.6 microg/100g diet) for 77 days. Feeding produced a significant elevation of MK-4 and MK-7 concentrations in the serum of OVX rats. In this case, a significant increase in the femoral MK-4 content was observed but MK-7 was not detected in the femoral tissues. OVX-induced decreases in the femoral dry weight and femoral calcium content were significantly prevented by the feeding of diets containing natto with MK-7 added (37.6 microg/100g diets). This study demonstrates that the intake of dietary MK-7 has a preventive effect on bone loss caused by OVX. This effect may be partly caused by MK-4, which is formed by degradation of MK-7.

MeSH terms

  • Animals
  • Bone Density / drug effects
  • Bone and Bones / drug effects
  • Bone and Bones / metabolism
  • Calcium / metabolism
  • Disease Models, Animal
  • Female
  • Fermentation
  • Osteocalcin / blood
  • Osteoporosis / etiology
  • Osteoporosis / metabolism
  • Osteoporosis / prevention & control*
  • Ovariectomy / adverse effects
  • Rats
  • Rats, Wistar
  • Soybeans
  • Vitamin K / administration & dosage
  • Vitamin K / analogs & derivatives*
  • Vitamin K / blood
  • Vitamin K / pharmacokinetics
  • Vitamin K 2 / analogs & derivatives

Substances

  • Osteocalcin
  • Vitamin K 2
  • Vitamin K
  • menatetrenone
  • vitamin MK 7
  • Calcium