Vitamin D, often called the “sunshine vitamin,” is a fat-soluble nutrient essential for bone health, immune function, and overall well-being. It helps the body absorb calcium and phosphorus, which are critical for strong bones and teeth. Vitamin D is produced by the skin when exposed to sunlight, but it can also be obtained through certain foods like fatty fish, fortified dairy products, and supplements. Deficiency can lead to weakened bones, fatigue, and immune system issues, making it vital for maintaining good health.