PATHOLOGY

Detailed explanation-1: -During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3.

Detailed explanation-2: -Vitamin D synthesis in the skin A whole body exposure to UVB radiation inducing the light pink color of the minimal erythema dose for 15–20 min is able to induce the production of up to 250 g vitamin D (10, 000 IU) [13], [14].

Detailed explanation-3: -The body creates vitamin D from direct sunlight on the skin when outdoors.

Detailed explanation-4: -Vitamin D production in the skin is the primary natural source of vitamin D, but many people have insufficient levels because they live in places where sunlight is limited in winter, or because they have limited sun exposure due to being inside much of the time.