What vitamin does the skin produce?

The skin produces vitamin D when exposed to ultraviolet (UV) radiation from the sun. This process begins when UV rays hit the skin, prompting a chemical reaction that converts a cholesterol-like substance in the skin into vitamin D3 (cholecalciferol). This precursor is then transformed in the liver and kidneys into the active form of vitamin D, which plays a vital role in calcium absorption and bone health, among other functions.

The other vitamins listed are important for skin health but are not synthesized by the skin. Vitamin A, primarily obtained from dietary sources, is critical for skin maintenance and repair. Vitamin C is essential for collagen synthesis and has antioxidant properties but is also acquired through nutrition. Vitamin E, known for its role as an antioxidant, protects cell membranes and supports skin health, but it is similarly sourced from dietary intake rather than being synthesized by the skin.