Vitamin C Enhances Skin Thickness by Activating Growth-Related Genes

Recent research conducted by scientists at the Tokyo Metropolitan Institute for Geriatrics and Gerontology has uncovered a significant role of vitamin C (VC) in promoting skin regeneration and thickness. As skin ages, it tends to thin and become less resilient—particularly in the outermost layer called the epidermis, which mainly comprises keratinocytes. These cells originate from deeper layers and migrate outward, forming a protective barrier. Improving this layer is vital for maintaining skin health and defense.

Vitamin C is well-known for its antioxidant properties and its benefits for skin health, including collagen production. However, new findings reveal that VC also directly activates genes responsible for skin cell growth and renewal by promoting epigenetic modifications, specifically DNA demethylation. This process involves removing methyl groups from DNA, which reactivates genes that drive cell proliferation and differentiation.

In the study, researchers applied VC to laboratory models of human epidermis, known as human epidermal equivalents, which simulate real skin conditions by allowing nutrient exchange while being exposed to the environment. Applying VC at concentrations similar to those transported from blood to skin led to noticeable thickening of the epidermis by day seven, with further thickening observed by day 14, indicating enhanced keratinocyte growth.

The investigation showed increased proliferation markers, such as Ki-67, in VC-treated skin. Additionally, VC facilitates the activity of TET enzymes, which are crucial for DNA demethylation. These enzymes convert methylated cytosines into hydroxymethylcytosines, a key step enabling gene expression. VC donates electrons to ensure TET enzyme activity remains optimal by maintaining the Fe+ state necessary for their function.

Further analysis identified over 10,138 regions of DNA that became hypomethylated with VC treatment. This demethylation was linked to the upregulation of 12 genes associated with cell growth and division, some showing a 1.6 to 75-fold increase in expression. When TET enzymes were inhibited, these effects reversed, confirming VC’s role in DNA demethylation-mediated gene activation.

These insights suggest that vitamin C can reinforce skin regeneration, particularly beneficial for aging or damaged skin, by boosting the genetic pathways involved in growth and repair. As Dr. Ishigami notes, "VC helps thicken the skin by encouraging keratinocyte proliferation through DNA demethylation, making it a promising treatment for skin thinning, especially in older adults."

This research underscores VC's potential as a key agent in skin health maintenance, offering hope for improved aging skin and recovery from skin damage.