The vitamin produced when the skin is exposed to sunlight is Vitamin D. When ultraviolet (UV) rays from the sun strike the skin, they trigger a chemical process that converts a cholesterol derivative into Vitamin D. This vitamin is crucial for various bodily functions, particularly in calcium absorption and bone health. A deficiency in Vitamin D can lead to health issues such as rickets in children and osteomalacia in adults. It also plays a role in immune system function and may have other health benefits. Due to limited sun exposure in some regions, Vitamin D can also be obtained through certain foods and supplements.