Exposure to sunlight helps to produce:

Appeared in: DSSSB 13 August 2024

Explanation

Vitamin D is often called the 'sunshine vitamin' because it is synthesized in the skin upon exposure to sunlight.
Specifically, ultraviolet B (UVB) radiation from the sun acts on a precursor molecule in the skin called 7-dehydrocholesterol.
This photochemical reaction converts 7-dehydrocholesterol into pre-vitamin D₃, which then isomerizes into Vitamin D₃ (cholecalciferol).
This endogenously produced Vitamin D is crucial for calcium absorption and bone health.

Option A: The Vitamin B complex consists of several water-soluble vitamins that the body cannot produce. They must be obtained through dietary sources.
Option B: Vitamin A is a fat-soluble vitamin that is obtained from the diet, either as preformed Vitamin A (retinol) from animal products or as provitamin A carotenoids (like beta-carotene) from plants.
Option C: Vitamin C (ascorbic acid) is an essential water-soluble vitamin that humans cannot synthesize and must be acquired through diet, primarily from fruits and vegetables.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Endogenous synthesis of vitamins and the role of sunlight in Vitamin D production as background academic context rather than a clinical decision trigger.
Nurses often educate patients on the importance of safe sun exposure for maintaining adequate Vitamin D levels, which is vital for calcium and phosphate absorption, bone mineralization, and immune function.
Vitamin D deficiency is a major public health concern, leading to rickets in children (softening and weakening of bones) and osteomalacia or osteoporosis in adults.
Nurses should assess patients for risk factors of Vitamin D deficiency, such as limited sun exposure, darker skin pigmentation, obesity, and certain medical conditions, and advise on dietary supplementation if necessary.

How to Approach the Question

First, identify the key elements of the question: 'sunlight' and 'produce' (synthesize).
The question asks which vitamin is produced in the body as a result of sun exposure.
Recall common knowledge about vitamins. Vitamin D is widely known as the 'sunshine vitamin'.
Evaluate the options based on this knowledge. Vitamins A, B, and C are known to be essential nutrients obtained from food.
Confirm that Vitamin D is the only option synthesized by the body through the action of sunlight on the skin.
Therefore, select Vitamin D as the correct answer.

Concept Tested & Keywords

Concept Tested: Endogenous synthesis of vitamins and the role of sunlight in Vitamin D production.
Stem keywords: sunlight, exposure, produce
Lead-in keywords: BEST, MOST RELEVANT CLUE
Negative lead-in flag: false

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E6 Medicine Harrison 22e Part 1 pp. 471-473, 472-474

Practise the full DSSSB 13 August 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.