| 摘要 |
PROBLEM TO BE SOLVED: To obtain a composition containing vitamin K effective for prevention or treatment of bone disease such as osteoporosis and having high safety, and further to provide a method for preparing the composition containing the vitamin K in a high content by a relatively simple treating method from a natural material. SOLUTION: This composition contains vitamin K included at least in the leaf part of Ipomea batatas as an active ingredient for promoting osteogenesis. The composition is prepared by heating the leaf part of the Ipomea Batatas to soften the tissue thereof, and carrying out a solid-liquid separation of a liquid mesophyll part, and a solid petiolate part and vein part to concentrate the vitamin K included in the mesophyll part. The composition can be also prepared by carrying out an extracting treatment of a dried material of the leaf part with a liquefied carbon dioxide in a supercritical state to concentrate the vitamin K included in the leaf part. A stem part of the Ipomea Batatas in combination with the leaf part can be used as a material to be treated in the preparing method. |
