Vitamin D is vital for the health of almost every organ and tissue in the body. While often associated with bone health and immunity, it also supports brain function, mood, skin, muscles, and the cardiovascular system. Acting like a hormone, vitamin D influences gene expression, helping regulate sleep, memory, and inflammation. Deficiency in vitamin D can lead to sleep issues, mood disorders, autoimmune conditions, and bone problems. Its anti-inflammatory properties also benefit the immune system, heart, and even insulin regulation. Maintaining healthy vitamin D levels is essential for overall well-being.