Department of Nutrition and Food Sciences, Texas Woman's University, Denton, TX 76209, USA.
Nutrients. 2022 Jul 19;14(14):2952. doi: 10.3390/nu14142952.
Vitamin A is a fat-soluble micronutrient necessary for the growth of healthy skin and hair. However, both too little and too much vitamin A has deleterious effects. Retinoic acid and retinal are the main active metabolites of vitamin A. Retinoic acid dose-dependently regulates hair follicle stem cells, influencing the functioning of the hair cycle, wound healing, and melanocyte stem cells. Retinoic acid also influences melanocyte differentiation and proliferation in a dose-dependent and temporal manner. Levels of retinoids decline when exposed to ultraviolet irradiation in the skin. Retinal is necessary for the phototransduction cascade that initiates melanogenesis but the source of that retinal is currently unknown. This review discusses new research on retinoids and their effects on the skin and hair.
维生素 A 是一种脂溶性微量营养素，对健康皮肤和毛发的生长必不可少。然而，维生素 A 摄入过少或过多都会产生有害影响。视黄酸和视黄醛是维生素 A 的主要活性代谢物。视黄酸以剂量依赖的方式调节毛囊干细胞，影响毛发周期、伤口愈合和黑素细胞干细胞的功能。视黄酸还以剂量依赖和时间依赖的方式影响黑素细胞的分化和增殖。皮肤受到紫外线照射时，类视黄醇水平会下降。视黄醛是启动黑色素生成的光转导级联所必需的，但目前尚不清楚其来源。本文综述了有关视黄醇及其对皮肤和毛发影响的新研究。
