维生素A的功效与作用
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1、保护眼睛
从“抗干眼维生素”这一别称就能看出,维生素A对保护眼睛、治疗各种眼疾有极好的功效。它不但影响泪液的分泌,还能帮助眼睛适应外界光线的强弱,维持人在黑暗中的视力,是保护眼睛健康不可缺少的重要营养素,多食用含有维生素A的食物对视力发育大有裨益。
2、促进骨骼牙齿的生长发育
维生素A对骨骼的生长发育同样有重要的作用。它能使未成熟的细胞转化为骨细胞,使骨细胞数目增多,从而促进骨骼、牙齿的生长发育。
3、保护组织器官
维生素A还能促使黏液的分泌,保护身体的组织器官,使这些组织发挥正常的功能,防治被细菌感染,并能维持呼吸系统健康运作。
4、增强抵抗力
据临床观察研究发现,维生素A能提高机体的细胞免疫与体液免疫作用,增强抗感染能力和对疾病的抵抗力。儿童服用维生素A,可明显减少呼吸道感染的次数或缩短病程、减轻症状。组织间黏多糖的合成也离不开维生素A,它对细胞起着黏合和保护作用。例如它可以保护皮肤、鼻、咽喉、呼吸器官的内膜、消化系统及泌尿生殖道上皮组织的健康,降低其被传染的几率,增强身体对传染病及寄生虫感染的抵抗力。
When you are old and grey and full of sleep,
And nodding by the fire, take down this book,
And slowly read, and dream of the soft look
Your eyes had once, and of their shadows deep; How many loved your moments of glad grace, And loved your beauty with love false or true,
But one man loved the pilgrim soul in you,
And loved the sorrows of your changing face; And bending down beside the glowing bars, Murmur, a little sadly, how love fled
And paced upon the mountains overhead
And hid his face amid a crowd of stars.
The furthest distance in the world
Is not between life and death
But when I stand in front of you
Yet you don't know that
I love you.
The furthest distance in the world
Is not when I stand in front of you
Yet you can't see my love
But when undoubtedly knowing the love from both
Yet cannot be together.
The furthest distance in the world
Is not being apart while being in love
But when I plainly cannot resist the yearning
Yet pretending you have never been in my heart. The furthest distance in the world
Is not struggling against the tides
But using one's indifferent heart
To dig an uncrossable river
For the one who loves you.