Steps to vitamin D synthesis and it's effects

Step three

Calcidiol returns to the blood once again where transport to the kidneys then allows the final conversion to Calcitrol

Step four

Now in the most active form, Calcitrol asked to increase blood calcium by acting on three target organs: The small intestine, skeleton, and the kidneys.

Step one

Sunlight contacting the epidermis converts seven dehydrocholesterol to vitamin D3, otherwise known as cholecalciferol

Step two

Transported via the blood to the liver, cholecalciferol is converted to calcidiol