Vitamin D.sub.2 analogs in which a cyclopropane ring is introduced onto the 24-carbon of the side chain of 1.alpha.,25-dihydroxyvitamin D.sub.2 and 1.alpha.-hydroxyvitamin D.sub.2. The compounds are characterized by a marked intestinal calcium transport activity while exhibiting much lower activity than 1.alpha.,25-dihydroxy-vitamin D.sub.3 in their ability to mobilize calcium from bone. Because of their preferential calcemic activity, these compounds would be useful for the treatment of diseases where bone formation is desirbed, such as osteoporosis.