What is an important vitamin that is formed in the skin when exposed to sunlight?

Vitamin D is an important vitamin that the skin synthesizes when exposed to ultraviolet (UV) rays from sunlight. When UVB rays hit the skin, they convert 7-dehydrocholesterol, a compound found in the skin, into pre-vitamin D3, which is then transformed into active vitamin D through further processes in the liver and kidneys.

Vitamin D plays a crucial role in various bodily functions, including calcium and phosphorus metabolism, which are essential for maintaining healthy bones and teeth. It also supports immune function and has various other roles in the body. This ability of the skin to produce vitamin D in response to sunlight is a unique feature, highlighting the connection between environmental factors and nutrient synthesis within the body.

The other vitamins mentioned—A, C, and E—are not produced in the skin in response to sunlight and have different roles and sources in the diet.