Sunlight exposure significantly affects vitamin D levels. When skin is exposed to UVB rays from sunlight, it synthesizes vitamin D, essential for calcium absorption and bone health. Adequate levels of vitamin D play a critical role in supporting the immune system and reducing the risk of certain diseases. Insufficient sunlight exposure can lead to deficiency, promoting conditions such as osteoporosis and increasing susceptibility to infections. Consequently, moderate sun exposure, along with dietary sources of vitamin D, is important for maintaining optimal health.