Sun's ultraviolet light is a good source of which vitamin?

Appeared in: NHM UP Staff Nurse-2023 shift 1st

Explanation

Vitamin D is uniquely known as the 'sunshine vitamin' because it is synthesized in the skin upon exposure to sunlight.
Ultraviolet B (UVB) radiation from the sun acts on a precursor molecule, 7-dehydrocholesterol, present in the skin.
This reaction converts 7-dehydrocholesterol into cholecalciferol, or Vitamin D3.
Vitamin D3 is then transported to the liver and kidneys, where it is converted into its biologically active form, calcitriol.
Active Vitamin D is essential for promoting the absorption of calcium and phosphorus from the intestine, which is critical for normal bone mineralization and health.

Option A: Vitamin K is not synthesized by sun exposure. Its primary role is in blood coagulation.
Option B: Vitamin E is a fat-soluble antioxidant obtained from dietary sources like nuts and oils, not from sunlight.
Option C: Vitamin A is essential for vision and is obtained from dietary sources such as carrots and liver, not from sun exposure.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Sources of Vitamins as background academic context rather than a clinical decision trigger.
Nurses play a key role in educating patients about safe sun exposure to maintain adequate Vitamin D levels while minimizing the risk of skin cancer.
It is important to identify and screen at-risk populations for Vitamin D deficiency, including the elderly, individuals with dark skin pigmentation, those with limited sun exposure (e.g., institutionalized patients), and people living in high latitudes with less winter sun.
Deficiency in children can lead to rickets (bone deformities), while in adults it can cause osteomalacia (softening of bones).

How to Approach the Question

This is a factual recall question that tests your knowledge of basic nutrition.
First, identify the keywords in the question stem: 'Sun's ultraviolet light' and 'vitamin'.
The question asks which vitamin is sourced from sunlight.
Recall the common names and primary sources of the vitamins listed in the options.
Associate 'sunlight' with the common name 'sunshine vitamin'.
Select the option that matches this association, which is Vitamin D.

Concept Tested & Keywords

QNjLto0_U0ipaK6GMe142m

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 519-521

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart A (pp 1-239 of 478) p. 123-125

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) p. 152-154

Practise the full NHM UP Staff Nurse-2023 shift 1st

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