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Which vitamin is synthesized by the human body upon exposure to sunlight?
Vitamin A
Vitamin B12
Vitamin C
Vitamin D
Vitamin D
Vitamin D is synthesized in the human skin when it is exposed to ultraviolet B (UVB) rays from sunlight. The ultraviolet radiation converts 7-dehydrocholesterol in the skin cells into cholecalciferol, the precursor of active Vitamin D.
Vitamin D is synthesized in the human skin when it is exposed to ultraviolet B (UVB) rays from sunlight. The ultraviolet radiation converts 7-dehydrocholesterol in the skin cells into cholecalciferol, the precursor of active Vitamin D.
Think of your skin as a tiny solar panel where sunlight acts as the power source to jumpstart the chemical manufacturing of an essential nutrient.
D for Daylight: Daylight provides Vitamin D!
7-Dehydrocholesterol+UVB\rightarrow \text{Cholecalciferol (Vitamin }$$D_3)
When skin absorbs UVB radiation with wavelengths between 290┬аnm and 315┬аnm, it triggers a photochemical reaction. Specifically, provitamin D3 (7-dehydrocholesterol) undergoes photolysis to form previtamin D3, which then thermally isomerizes into cholecalciferol (Vitamin D3). This compound is subsequently transported to the liver and kidneys to be hydroxylated into its active hormonal form, calcitriol.
Vitamin D is uniquely synthesized by the human body via sunlight exposure, unlike most other vitamins.
It plays a crucial role in calcium and phosphorus homeostasis, promoting bone mineralization.
Deficiency of Vitamin D leads to rickets in children and osteomalacia in adults.
Enhances calcium absorption in the gut
Supports immune function and neuromuscular health
Excessive exposure to UVB rays can cause skin damage and increase the risk of skin cancer
Bone health maintenance
Prevention of bone-softening diseases like rickets
Option A (Vitamin A) is a fat-soluble vitamin found in carrots and liver, essential for vision.
Option B (Vitamin B12) is a water-soluble vitamin produced by bacteria and found in animal products.
Option C (Vitamin C) is a water-soluble antioxidant found abundantly in citrus fruits.
D is correct тАФ Vitamin D is synthesized in the human skin through the action of ultraviolet B rays from sunlight on 7-dehydrocholesterol.
In competitive exams like RRB JE, remember that fat-soluble vitamins include A, D, E, and K, while B-complex and C are water-soluble.
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