Vitamin A is an important micro-essential nutrient, whose primary dietary source is retinyl esters. In addition, β-carotene (pro-vitamin A) is a precursor of vitamin A contained in green and yellow vegetables that is converted to retinol in the body after ingestion. Retinol is oxidized to produce visual retinal, which is further oxidized to retinoic acid (RA), which is used as a therapeutic agent for patients with promyelocytic leukemia. Thus, the effects of retinal and RA are well known. In this paper, we will introduce (1) vitamin A circulation in the body, (2) the actions and mechanisms of retinal and RA, (3) retinoylation: another RA mechanism not depending on RA receptors, (4) the relationship between cancer and actions of retinol or β-carotene, whose roles in vivo are still unknown, and (5) anti-cancer actions of vitamin A derivatives derived from fenretinide (4-HPR). We propose that vitamin A nutritional management is effective in the prevention of cancer.

维生素A是一种重要的微量必需营养素，其主要膳食来源是视黄酯。此外，β-胡萝卜素（维生素 A 原）是绿色和黄色蔬菜中所含维生素 A 的前体，摄入后在体内转化为视黄醇。视黄醇被氧化产生视觉视黄醛，视黄醛进一步被氧化为视黄酸（RA），用作早幼粒细胞白血病患者的治疗剂。因此，视网膜和RA的作用是众所周知的。在本文中，我们将介绍（1）维生素A在体内循环，（2）视网膜和RA的作用和机制，（3）视黄酰化：另一种不依赖于RA受体的RA机制，（4）癌症之间的关系和视黄醇或β-胡萝卜素的作用，它们在体内的作用仍然未知，以及（5）源自芬维A胺（4-HPR）的维生素A衍生物的抗癌作用。我们建议维生素 A 营养管理可有效预防癌症。