Vitamin related with Ultra violet Rays is?

Appeared in: MNS 2015

Explanation

Vitamin D is uniquely synthesized in the skin through the action of ultraviolet (UV) rays from the sun.
Specifically, UVB radiation converts 7-dehydrocholesterol in the skin to cholecalciferol (Vitamin D₃).
This vitamin is crucial for calcium and phosphate absorption, making it essential for bone mineralization and health.
Deficiency, often due to lack of sun exposure, leads to conditions like rickets in children and osteomalacia in adults.

Option A: Vitamin E is a dietary antioxidant obtained from foods like nuts and seeds. It is not synthesized in the body through UV light exposure.
Option B: Vitamin K is essential for blood coagulation. It is acquired through diet (leafy greens) and synthesis by intestinal bacteria, not through sunlight.
Option D: Vitamin A is vital for vision and immune function. It is obtained from the diet in the form of retinol (from animal sources) or beta-carotene (from plants), not from UV exposure.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Vitamin Synthesis and Sources as background academic context rather than a clinical decision trigger.
Nurses often advise patients on the importance of safe, moderate sun exposure (e.g., 10-30 minutes several times a week) to maintain adequate Vitamin D levels.
Screening for Vitamin D deficiency is crucial in high-risk groups, including the elderly, obese individuals, people with limited sun exposure, and those with malabsorption syndromes.
What if the patient has chronic kidney disease? They would be unable to perform the final activation step (converting 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol/calcitriol). Therefore, they would require supplementation with the active form of Vitamin D (calcitriol) rather than standard Vitamin D₃, as sun exposure alone would be insufficient.

How to Approach the Question

Identify the key terms in the question: 'Vitamin' and 'Ultra violet Rays'.
Recall the basic properties of the vitamins listed in the options.
Associate 'Ultra violet Rays' or 'sunlight' with the synthesis of one of the vitamins. Vitamin D is famously known as the 'sunshine vitamin'.
Evaluate each option based on this knowledge:
Vit. E is an antioxidant.
Vit. K is for blood clotting.

Concept Tested & Keywords

QtE-bVfLUqIpSCQLTeDoqM

E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) p. 150-152

E6 One Stop Resource all for your Exam Needs in Biochemistry (pp 6-135 of 140) pp. 78-80, 76-78

Practise the full MNS 2015

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