维生素A不仅广泛存在于多种水果和蔬菜，及蛋类、牛奶和肉类，及含脂肪丰富的海水鱼类，亦可人工合成/Vitamin A is a vitamin. It can be found in many fruits, vegetables, eggs, whole milk, butter, fortified margarine, meat, and oily saltwater fish. It can also be made in a laboratory.

维生素A可用于治疗维生素A缺乏所导致的多种疾病或异常，或是减少某些疾病的并发症/Vitamin A is used for treating vitamin A deficiency. It is also used to reduce complications of diseases such as malaria, HIV, measles, and diarrhea in children with vitamin A deficiency.

可用于调理女性更年期前后的不适，及其治疗乳房纤维腺瘤和预防乳腺癌/Women use vitamin A for heavy menstrual periods, premenstrual syndrome (PMS), vaginal infections, yeast infections, “lumpy breasts” (fibrocystic breast disease), and to prevent breast cancer. Some women with HIV use vitamin A to decrease the risk of transmitting HIV to the baby during pregnancy, childbirth, or breast-feeding.

可提升男性的精子数量/Men use vitamin A to raise their sperm count.

可增加视力和治疗眼部疾病/Some people use vitamin A for improving vision and treating eye disorders including age-related macular degeneration (AMD), glaucoma, and cataracts.

有利于皮肤健康/Vitamin A is also used for skin conditions including acne, eczema, psoriasis, cold sores, wounds, burns, sunburn, keratosis follicularis (Darier’s disease), ichthyosis (noninflammatory skin scaling), lichen planus pigmentosus, and pityriasis rubra pilaris.

可用于治疗胃肠疾病、枯草热和泌尿系统感染等/It is also used for gastrointestinal ulcers, Crohn’s disease, gum disease, diabetes, Hurler syndrome (mucopolysaccharidosis), sinus infections, hayfever, and urinary tract infections (UTIs).

Vitamin A is also used for shigellosis, diseases of the nervous system, nose infections, loss of sense of smell, asthma, persistent headaches, kidney stones, overactive thyroid, iron-poor blood (anemia), deafness, ringing in the ears, and precancerous mouth sores (leukoplakia).

Other uses include preventing and treating cancer, protecting the heart and cardiovascular system, slowing the aging process, and boosting the immune system.

Vitamin A is applied to the skin to improve wound healing, reduce wrinkles, and to protect the skin against UV radiation.

How does it work?

维生素A对维护人类眼、皮肤和免疫系统的正常功能具有非常重要的功效/Vitamin A is required for the proper development and functioning of our eyes, skin, immune system, and many other parts of our bodies.

(From:webmd.com)