Vitamin D₃ Photosynthesis in Skin

7-Dehydrocholesterol → Previtamin D₃ → Vitamin D₃

Visão geral

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.

Exemplo do cotidiano

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

Importância industrial

A deficiência de vitamina D afeta mais de mil milhões de pessoas em todo o mundo, impulsionando a procura de suplementos e alimentos fortificados com UV.

Propriedades

Tipo: Photochemical
Reversível: Não
Energia: Endotérmico

Reações relacionadas

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).