Vitamin D₃ Photosynthesis in Skin

7-Dehydrocholesterol → Previtamin D3 → Vitamin D3

개요

UV-B radiation (280–315 nm) converts 7-dehydrocholesterol in the skin to previtamin D₃ through a photochemical ring-opening reaction. Previtamin D₃ then thermally isomerizes to cholecalciferol (vitamin D₃). This is the primary source of vitamin D for most people and requires about 10–30 minutes of midday sun exposure.

일상 속 예시

Spending 15–20 minutes in midday sunshine produces about 10,000–20,000 IU of vitamin D₃, far more than any food source.

산업적 중요성

비타민 D 결핍은 전 세계 10억 명 이상에게 영향을 미쳐, 보충제와 자외선 강화 식품의 수요를 이끌고 있습니다.

성질

유형
Photochemical
가역 반응
아니오
에너지
흡열

관련 반응

Photochemical Smog Formation (NO₂ Photolysis) Photochromism of Spiropyran Chlorophyll Fluorescence Photodegradation of Methylene Blue by TiO₂ Photodissociation of Chlorine Gas Silver Bromide Photodecomposition Cis-Trans Isomerization of Retinal Photosynthesis Ozone Formation by UV Light Dye-Sensitized Solar Cell (Grätzel Cell)

Frequently Asked Questions

What is the equation for Vitamin D₃ Photosynthesis in Skin?
The balanced equation is: 7-Dehydrocholesterol → Previtamin D₃ → Vitamin D₃.
What type of reaction is Vitamin D₃ Photosynthesis in Skin?
Vitamin D₃ Photosynthesis in Skin is a photochemical reaction.
Is Vitamin D₃ Photosynthesis in Skin exothermic or endothermic?
Vitamin D₃ Photosynthesis in Skin is endothermic (absorbs energy).