关键区别 - 维生素A与β胡萝卜素
在维生素A和β-胡萝卜素之间的差异上似乎有很多困惑。维生素A是脂溶性维生素and represents a group of unsaturated nutritional organic composites; that comprises retinol, retinal, retinoic acid, and several provitamin A carotenoids, and beta-carotene. Vitamin A is particularly significant for the health of the eyes, lungs, bones, skin, immune system, and protein synthesis.β-胡萝卜素是一种亲维生素A,也是最丰富和知名的胡萝卜素。This is thekey differencebetween vitamin A and beta carotene. Beta-carotene is originated in the red, orange, and yellow colored fruits and vegetables. Pro-vitamin A (beta-carotene and other carotenes) can be converted in the human body into retinol (vitamin A). In this article, let’s elaborate the difference between vitamin A and beta-carotene in terms of their intended uses and other chemical characteristics.
什么是维生素A?
Vitamin A (retinol) is a vitamin and is essential for life and overall health. It is a family of substances called维他命原一并作为pre-formed vitamin A。预先形成的维生素A已经形成为维生素A,它包含各种形式的视黄醇,视网膜和视黄酸。然而,科学家在提到维生素A时经常使用视黄醇一词。预形成的维生素A仅起源于动物产品,例如鱼类和乳制品。几个亲维生素A包括carotenoidsand beta-carotene, and they can be converted into pre-vitamin compounds inside the human body.
Vitamin A has numerousfunctions in the human body。它的增长具有重要意义nd development, for the maintenance of theimmune systemas well as good vision. Vitamin A is required by the retina of the eye in the form of retinal, which reacts with protein opsin to synthesize rhodopsin, the light-sensitive molecule required for both low-light vision and color vision. In addition to that, an irreversibly oxidized form of retinol or retinoic acid has a very different which is an essential hormone-like growth factor for上皮and other cells. Retinol and other pre-forms are metabolized in the body and stored in the liver, principally as retinyl palmitate. Vitamin A in the bloodstream is known as serum retinol and is assessed in “retinol equivalents”.
What is Beta Carotene?
β-胡萝卜素是各种可食用植物和水果中丰富的颜色颜色橙色的色素。它是一种有机络合物,化学分类为a烃and precisely作为萜类化合物,从异戊二烯单元中复制其派生。它是四门苯丙烯和胡萝卜素的家伙。胡萝卜素是从八个异戊二烯单元中合成的生化,因此具有40碳。在这类胡萝卜素类别中,β-胡萝卜素是众所周知的,它在长链分子的两端都有β-环。β-胡萝卜素富含胡萝卜,南瓜和红薯,可促成其橙色。除此之外,β-胡萝卜素是丙二胺A,可从一个β-胡萝卜素分子合成视黄醇的两个分子(前体Vitamin A)。
What is the difference between Vitamin A and Beta Carotene?
Vitamin Group:
Vitamin A是一种脂溶性维生素。它是一组不饱和的营养有机化合物。其中包括视黄醇,视网膜,视黄酸和几种普provitamin A类胡萝卜素和β-胡萝卜素。
Beta-caroteneis a provitamin A.
Chemical Structure:
All types ofvitamin Ahave a beta-ionone ring to which an isoprenoid chain is attached, known as a retinyl group. This is vital for vitamin activity.
Beta-carotene有两个连接的视网膜基团。
Synthesis:
Vitamin A不能转换为β-胡萝卜素。
Beta-carotene可以转化为维生素A。一个β-胡萝卜素的一个分子可以产生两个分子的视黄醇。酶β-胡萝卜素15,15'-二氧酶切割肠粘膜中的β-胡萝卜素,并将其转化为视黄醇。由于β-胡萝卜素在消化道培养基中的溶解度非常差,因此这种转化效率较低。因此,需要12 mg的β-胡萝卜素才能产生1 mg视黄醇。
资源:
说Vitamin A, Retinol is mainly found in animal food sources such as yellow and fat-soluble food substance. It is rich in cod liver oil, liver, milk, butter, and eggs.
Beta-carotenedirectly contributes to the orange color of many different fruits and vegetables. Crude palm oil, as well as yellow and orange fruits, such as cantaloupe, mangoes, pumpkin and papayas, and orange, root vegetables such as carrots and yams are particularly rich sources of beta-carotene. The color of beta-carotene is masked by叶绿素pigments in green leafy vegetables and edible green leaves such as spinach, kale, sweet potato leaves, and sweet gourd leaves. Therefore, they are also rich in beta-carotene.
Significance:
Vitamin Ais important for vision cycle, maintenance of the immune system, growth and development, gene transcription, embryonic development, and reproduction, Bone metabolism andantioxidantactivity
Beta-carotene用于营养补充剂作为促抗通过A。它是一种强大的抗氧化剂。另外,它是橙色颜料,用作颜色添加剂。它是E数字E160A。
Side Effects:
过多的vitamin Aconsumption can cause nausea, petulance, reduced appetite, vomiting, blurry vision, nuisances, hair loss, muscle and stomach pain and weakness, sleepiness, and changed mental status.
过度最常见的副作用β-胡萝卜素consumption is carotenoderma (orange skin)
总之,维生素A和β-胡萝卜素是人体的必需营养素。维生素A是一种从β-胡萝卜素合成的必需脂溶性维生素。β-胡萝卜素具有不同的食物应用,它是pro-VitaminA。
参考
Aktkuna D, et al., Beta-carotene, vitamin A and carrier proteins in thyroid processes.ActaMedicaAustriaca, 1993;20 (1-2):17-20.
Radhika MS, et al. Effects of vitamin A deficiency during pregnancy on maternal and child health.Brit J Gyn, (2002) Jun;109(6):689-93.
Sklan D. Vitamin A in human nutrition. Progressive Food and Nutrition Sciences, 1987;11(1):39-55.
Image Courtesy:
1.Retinol由dwmyers(en:image:retinol.png)[GFDL或者CC-BY-SA-3.0],通过Wikimedia Commons
2. “Carrots” by Kander – Own work. [Public Domain] via Commons
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