缺乏维生素A会影响眼睛的发育,它主要存在干什么当中?

2025-04-03 09:29:51
推荐回答(4个)
回答1:

维生素A 主要存在下面食品中:

天然维生素A只存在于动物性食品如:动物肝脏、蛋类、奶油和鱼肝油中;植物所含的胡萝卜素进入人体,可在肝中转变为维生素A(1毫克胡萝卜素=0.167毫克维生素A)。

维生素A能促进生长发育,保护夜间视力,可增加抗病力和抗癌作用。维生素A缺乏可导致儿童生长迟滞、发育不良、患夜盲症,但切不可摄人过多,以免造成慢性中毒。红黄色蔬菜、水果和绿叶菜中含有较多的胡萝卜素。

富含维生素A的食物主要有动物的肝脏、鱼类、海产品、奶油和鸡蛋等动物性食物。此外咸带鱼、鲫鱼、白鲢、鳝鱼、鱿鱼、蛤蜊、奶油、人奶、牛奶等也含有140~846国际单位的维生素A(每100克)。

富含胡萝卜素的食物主要是橙黄色和绿色蔬菜。菠菜、胡萝卜、韭菜、油菜、荠菜、马兰头等每500克可含胡萝卜素14毫克以上,每天只要吃120~150克就能满足儿童维生素A的需要。雪里红、小白菜、红薯、大葱、西红柿、柿子椒等。每500克含胡萝卜素为1.5~7.4毫克。

只要注意选择食物,不偏食,满足一天的维生素A的需要并不难,但对于乳母、婴儿等一些特殊人群,完全从食物中满足需要则比较困难,可以用添加鱼肝油的办法,但要注意用量不宜过多。为了预防北方季节性的缺乏,最好在有绿叶菜季节,多吃一些富含胡萝卜素的蔬菜,使体内有一定的贮存。

回答2:

主要在人的视网膜中起着至关重要的作用,维生素A主要脂溶性的食物中,比如动物肝脏,牛奶,鸡蛋,瘦肉中含量都比较丰富。胡萝卜中含有大量维生素A原,在体内可以转化成更加有活性的维生素A。

回答3:

在食物当中。。。

回答4:

维护新陈代谢 保持健康

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