Which UV type is needed by humans for synthesis of vitamin D?

Prepare for the Surface Methods - Liquid Penetrant Inspection (LPI) Exam. Utilize flashcards and multiple-choice questions with detailed hints and explanations. Ace your exam with confidence!

Multiple Choice

Which UV type is needed by humans for synthesis of vitamin D?

Explanation:
Synthesis of vitamin D in the skin is driven by UVB radiation. When UVB photons (roughly 290–315 nm) strike 7-dehydrocholesterol in the epidermis, they break a bond and form previtamin D3, which then thermally isomerizes to vitamin D3. From there, it’s processed by the liver and kidneys to become the active form. UVA doesn’t efficiently trigger this photochemical step, and UVC is largely blocked by the atmosphere and would be harmful if it reached the skin. So UVB is the component of sunlight needed for vitamin D production.

Synthesis of vitamin D in the skin is driven by UVB radiation. When UVB photons (roughly 290–315 nm) strike 7-dehydrocholesterol in the epidermis, they break a bond and form previtamin D3, which then thermally isomerizes to vitamin D3. From there, it’s processed by the liver and kidneys to become the active form.

UVA doesn’t efficiently trigger this photochemical step, and UVC is largely blocked by the atmosphere and would be harmful if it reached the skin. So UVB is the component of sunlight needed for vitamin D production.

Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy