Generation of calcitriol in human body. Vitamins D2 and D3 are synthesized in the human body and converted in to 25-hydroxyvitamin D [25(OH)D] in the liver and to the active form 1,25-dihydroxyvitamin D [1,25(OH)2D] (calcitriol) in the kidney and target tissues. UVB: ultraviolet B
Note. Adapted from “Controlling chronic diseases and acute infections with vitamin D sufficiency’’ by Wimalawansa SJ. Nutrients. 2023;15:3623 (https://www.mdpi.com/2072-6643/15/16/3623). CC BY.