Teijin Limited

Junji Kubo

Seiichi Ishizuka

Kiyoshi Bannai

Tatuyuki Naruchi

Norio Ohnuma

The present invention relates to a method of controlling the concentration of calcium in the serum of warm-blooded animals characterized by the administration of a pharmaceutically effective amount of 25-hydroxyvitamin D.sub.3 -26,23-lactones expressed by the following formula (I) ##STR1## wherein R indicates a hydrogen atom or a hydroxyl group and X indicates --O-- or --O--O--, to warm-blooded animals, and a pharmaceutical composition to be used for controlling the concentration of calcium in the serum of warm-blooded animals which comprises 25-hydroxyvitamin D.sub.3 -26,23-lactones expressed by the above-mentioned formula (I) and a pharmaceutically acceptable carrier. 25-hydroxyvitamin D.sub.3 -26,23-lactones are desirably used especially for the treatment or prevention of the diseases resulting from the high calcium levels in the serum.

Methods of controlling the concentration of calcium in the serum of

Novel 1.alpha.-hydroxy-24-dehydrovitamin D.sub.3 and its hydroxyl-protected derivatives; novel 1.alpha.-hydroxy-24-dehydroprevitamin D.sub.3 and its hydroxyl-protected derivatives; and novel 1.alpha.,3.beta.-dihydroxycholesta-5,7,24-triene or its hydroxyl-protected derivatives which are key intermediates for preparing the aforesaid compounds. Novel processes for preparing these compounds are also provided. 1.alpha.-Hydroxy-24-dehydrovitamin D.sub.3 has a pharmacological action of controlling the calcium metabolism of warm-blooded animals, and is useful as a prophylactic or therapeutic pharmaceutical for vitamin D deficient disease and related diseases.

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Hachioji, Japan

Junji Kubo