佝偻病的多发群体是2岁以内的婴幼儿，其病因是人体缺乏下列哪种维生素?

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='31812' and id < 2542579 and id<>'2542579' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='31812' and id > 2542579 and id<>'2542579' order by id asc limit 5