Multiple choice general knowledge

Exposure to sunlight helps a person improve his health because

  1. the infrared light kills bacteria in the body

  2. resistance power increases

  3. the pigment cells in the skin get stimulated and produce a healthy tan

  4. the ultraviolet rays convert skin oil into Vitamin D
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sunlight exposure triggers vitamin D synthesis in skin cells - ultraviolet B rays convert 7-dehydrocholesterol (a skin oil compound) into previtamin D3, which becomes vitamin D3. This is essential for calcium absorption, bone health, and immune function. Infrared rays don't kill bacteria internally, and tanning is a side effect, not the health benefit.

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