Previtamiini

Previtamiini is a term used to describe a biologically inactive precursor molecule that can be converted into an active vitamin within the body. This conversion process typically involves enzymatic reactions or exposure to specific environmental factors like sunlight. Previtamins are important because they can be stored in the body in a stable form and then activated as needed. This mechanism allows for a more regulated supply of the active vitamin. A well-known example of a previtamin is provitamin D, specifically 7-dehydrocholesterol. When exposed to ultraviolet B (UVB) radiation from sunlight, 7-dehydrocholesterol in the skin undergoes a photochemical reaction, converting it into previtamin D3. This previtamin D3 then undergoes a heat-dependent isomerization to form vitamin D3. Other substances can also act as previtamins for different vitamins. The concept of previtamins highlights the complex metabolic pathways involved in nutrient utilization and demonstrates how the body can efficiently manage the storage and activation of essential compounds.

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