Which vitamin is commonly referred to as the "Sunshine Vitamin"?

Vitamin D is commonly referred to as the "Sunshine Vitamin" because it is produced in the skin in response to sunlight exposure. When ultraviolet B (UVB) rays from the sun hit the skin, a chemical reaction occurs that converts 7-dehydrocholesterol, a cholesterol derivative, into vitamin D3, which is then further converted in the liver and kidneys into its active form, calcitriol. This process makes sunlight a crucial factor in the body's ability to produce adequate levels of vitamin D, which is essential for maintaining healthy bones and supporting immune function.

Vitamin D also functions in regulating calcium and phosphate in the body, which are vital for maintaining healthy bones and teeth. Its relationship with sunlight makes it distinct from other vitamins that do not have a similar production mechanism linked to sun exposure. While vitamins C, A, and K have important roles in the body, they do not share this particular connection with sunlight and hence do not earn the "Sunshine Vitamin" title.