The Role of Vitamin A in Wound Healing

Abstract

Vitamin A is an essential micronutrient that comes in multiple forms, including retinols, retinals, and retinoic acids. Dietary vitamin A is absorbed as retinol from preformed retinoids or as pro–vitamin A carotenoids that are converted into retinol in the enterocyte. These are then delivered to the liver for storage via chylomicrons and later released into the circulation and to its biologically active tissues bound to retinol‐binding protein. Vitamin A is a crucial component of many important and diverse biological functions, including reproduction, embryological development, cellular differentiation, growth, immunity, and vision. Vitamin A functions mostly through nuclear retinoic acid receptors, retinoid X receptors, and peroxisome proliferator‐activated receptors. Retinoids regulate the growth and differentiation of many cell types within skin, and its deficiency leads to abnormal epithelial keratinization. In wounded tissue, vitamin A stimulates epidermal turnover, increases the rate of re‐epithelialization, and restores epithelial structure. Retinoids have the unique ability to reverse the inhibitory effects of anti‐inflammatory steroids on wound healing. In addition to its role in the inflammatory phase of wound healing, retinoic acid has been demonstrated to enhance production of extracellular matrix components such as collagen type I and fibronectin, increase proliferation of keratinocytes and fibroblasts, and decrease levels of degrading matrix metalloproteinases.

Intra-Individual Double Burden of Malnutrition among Adults in China: Evidence from the China Health and Nutrition Survey 2015

“…Actions therefore on improving the population's poor dietary calcium intake, such as nutritional interventions on increasing dietary intakes of milk and dairy products, are necessary to take. Dietary retinol, another key micronutrient concern, plays an important role in vision, immunity, embryological development, and growth hormone production [30]. A study presented that approximately 87% of Chinese adults consumed less retinol than the EAR, and only 6% of adults consumed more than Chinese recommended nutrient intake in 2015 [6].…”

Nutrition Therapy on Cutaneous Lymphoma Patient with Anemia and Hypoalbuminemia: A Case Report

“…In patients with extensive injuries, zinc supplementation can be given up to 40 mg/day. Standard preparations for cancer cachexia patient is 10-30 mg/day 11,19,20 .…”

Divergent color signals from homologous unfeathered ornaments in two congeneric grouse

“…One potential explanation for the presence of bright coloration in tissues not used as visual signals relates to the biological functions of carotenoid compounds, which likely contribute to the colorful appearance of air sacs in prairie‐chickens. Both carotenoids themselves and vitamin A, for which carotenoids serve as precursors (Simpson, ), have been linked with wound healing properties in the epidermal tissue of a variety of vertebrates (Meephasnan, Rungjang, Yingmema, Deenonpoe, & Ponnikorn, ; Polcz & Barbul, ). Although it is difficult to determine if prairie‐chickens specifically target combs and air sacs during aggressive encounters, we have observed injuries to combs and air sacs.…”

“…(c) Bootstrapped 95% confidence intervals of the standardized slope estimates for the effect of mass on air sac UV hue using 1,000 permutations of the linear mixed model hue and mass (R 2 < .01) in the Lesser Prairie-Chicken provides evidence against air sac color fulfilling a signaling function in this species.One potential explanation for the presence of bright coloration in tissues not used as visual signals relates to the biological functions of carotenoid compounds, which likely contribute to the colorful appearance of air sacs in prairie-chickens. Both carotenoids themselves and vitamin A, for which carotenoids serve as precursors(Simpson, 1983), have been linked with wound healing properties in the epidermal tissue of a variety of vertebrates(Meephasnan, Rungjang, Yingmema, Deenonpoe, & Ponnikorn, 2017;Polcz & Barbul, 2019). Although it is difficult to determine if prairie-chickensF I G U R E 8 Comparison of mass and air sac saturation (r-achieved) in Lesser and Greater Prairie-Chickens.…”