Vitamin A is an valuable nutrient - without it, the body can't function. It helps boost the immune system, aids in reproduction, helps build blood and bone, and keeps skin healthy. It's known by many names, but the most common is retinol, which might be recognizable as a substantial ingredient in many skin care products. additional forms of vitamin A add together retinal, alpha-carotene, beta-carotene, gamma-carotene, and crypto-carotene.