Vitamin D and Skin Function
Vitamin D and Skin Regulation. Vitamin D plays a central regulatory role in skin health by supporting barrier integrity, immune signalling, cellular turnover, and communication between the skin and the immune system. Rather than acting only as a nutrient produced in the skin, vitamin D helps maintain the biological environment required for normal skin function, resilience, and repair.
Vitamin D receptors are widely expressed in skin cells, including keratinocytes, immune cells, and cells involved in wound healing. Through these receptors, vitamin D influences how skin cells differentiate, respond to injury, and regulate local immune activity. Adequate vitamin D availability supports balanced cell renewal, controlled inflammation, and effective barrier maintenance.
Because the skin functions as both a protective barrier and an immune interface, vitamin D contributes indirectly by shaping signalling pathways that regulate antimicrobial defence, inflammatory responses, and tissue repair. Rather than driving rapid or isolated effects, vitamin D supports long-term skin stability by maintaining coordinated cellular and immune regulation.
Understanding the relationship between vitamin D and skin health helps explain why deficiency is associated with impaired barrier function, altered immune responses, and delayed repair rather than isolated skin symptoms. Vitamin D influences how the skin adapts to environmental stressors and maintains resilience over time.
This page focuses on skin regulation as one outcome of vitamin D physiology. Later sections explore how skin health interacts with immunity, inflammation, ageing processes, and overall systemic balance.