人体所需维生素D有两个来源:一是“外源性”;二是“内源性”。当外源性维生素D摄入不足或内源性维生素D生成减少,就会导致维生素D缺乏。其中,老年人、深色皮肤者、肥胖者、日晒不足等人群常会发生维生素D缺乏,应注意补充。老年人老年人常因食量减少或膳食结构不合理,导致外源性维生素D摄入不足;老年人的胃肠道疾患会影响 The human body needs two sources of vitamin D: one is “exogenous”; two is “endogenous”. Insufficient intake of exogenous vitamin D or reduced production of endogenous vitamin D can result in vitamin D deficiency. Among them, the elderly, dark skin, obesity, sun exposure and other people often occur vitamin D deficiency, should pay attention to add. Elderly people often due to reduced appetite or dietary structure is not reasonable, leading to inadequate intake of exogenous vitamin D; gastrointestinal disorders in the elderly will affect