The Sunshine Vitamin
Vitamin D is known as the "Sunshine" vitamin, and it is called that because it's produced in your skin in response to sunlight. It's a fat-soluble vitamin in a family of compounds that includes vitamins D-1, D-2, and D-3.
Vitamin D insufficiency or deficiency has increased in today's general population and has become an important public health issue. Vitamin D is mainly known for its favorable effects on the absorption of calcium and phosphorus as well as bone and teeth growth.
Vitamin D plays a very important role in keeping us healthy and fighting illness in the least destructive way by regulationg the immune response (the production of cytokines) without provoking an immune over-reaction such as the "cytokine storm" or hypercytokinemia (often associated with sever COVID-19 illness), and inhibiting the proliferation of pro-inflammatory cells, both of which are crucial for the manner of development of inflammatory diseases.