Which vitamin is synthesized directly within the skin upon exposure to sunlight?
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Answer: C. Vitamin D
Explanation
Ultraviolet B radiation from sunlight converts cholesterol precursors in the skin into vitamin D. This cutaneous biosynthesis pathway provides the primary natural source of vitamin D for humans. Sunlight exposure triggers the chemical conversion necessary to produce active vitamin D precursors. Vitamins are essential organic compounds that the human body often must obtain from external sources. Vitamin D functions biologically as a hormone regulating calcium and phosphorus absorption in bones. Geographic location, season, and skin pigmentation influence the efficiency of cutaneous synthesis.
Adequate sun exposure prevents bone softening disorders like rickets and promotes skeletal health. Dermatologists balance recommendations for safe sun exposure against the risk of skin damage. Fortified foods and supplements help individuals maintain adequate vitamin D levels during winter months. Vitamin A is obtained primarily through dietary sources such as liver, dairy, and orange vegetables. Vitamin C is a water-soluble antioxidant found abundantly in citrus fruits and fresh vegetables. Vitamin K is synthesized by intestinal bacteria and absorbed from green leafy plant foods.
- Subject
- Everyday Science
- Category
- Everyday Science
- Topic
- —
- Difficulty
- medium
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