The vitamin known to be synthesized by the skin when exposed to sunlight is vitamin D. This crucial nutrient aids in the absorption of calcium and phosphate, which are essential for maintaining healthy bones and teeth. Vitamin D also plays a vital role in supporting the immune system and regulating various cellular functions. Exposure to sunlight triggers the body to produce vitamin D, making it an important factor in maintaining overall health. However, individuals with limited sun exposure or certain dietary restrictions may require supplements or fortified foods to meet their vitamin D needs.