Vitamin D is basically a hormone. Vitamin D is produced in the skin when exposed to sunlight. This is also the reason why we speak of the sun hormone. Its chemical name is cholecalciferol.

Metaphorically speaking, vitamin D brings light into the cells. For vitamin D to work, it needs to be activated in two more steps.
The first activation step takes place in the liver. From vitamin D, the 25-hydroxy vitamin D is created. Continue reading →