Which of the following is a therapeutic effect of UV light therapy?

• A. Vitamin D Production
• B. Cooling Of The Skin
• C. Hair Growth
• D. Increased Sweating

Answer: (A)

UV exposure can stimulate the skin to make vitamin D. UVB photons convert 7-dehydrocholesterol in the skin into previtamin D3, which is then transformed into vitamin D3 and eventually activated in the liver and kidneys. This vitamin D is essential for calcium absorption and bone health, so generating it through skin synthesis is a beneficial, systemic effect of UV therapy. The other options don’t represent what UV light therapy does: cooling the skin isn’t produced by UV exposure, hair growth isn’t a direct result, and increased sweating isn’t an effect of UV therapy.