Which of the following fat-soluble vitamins have an antioxidant function?

Appeared in: UPUMS Nsg officer-2023

Explanation

Vitamin E (tocopherol) is the principal fat-soluble antioxidant in the body.
Its primary function is to protect cell membranes from oxidative damage by neutralizing free radicals.
It specifically prevents the oxidation of polyunsaturated fatty acids (PUFAs) within cell membranes, a process called lipid peroxidation.
This antioxidant action is vital for maintaining the structural and functional integrity of all cells.

Option B: Vitamin D's primary role is not as an antioxidant. It functions as a hormone to regulate calcium and phosphate levels, which is essential for bone mineralization and health.
Option C: While some precursors of Vitamin A (like beta-carotene) have antioxidant activity, the primary functions of Vitamin A (retinol) itself are related to vision, immune response, and cell differentiation.
Option D: Vitamin K is not an antioxidant. Its essential function is in blood coagulation, where it acts as a coenzyme for the synthesis of clotting factors in the liver.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Functions of fat-soluble vitamins as background academic context rather than a clinical decision trigger.
Nurses should educate patients on dietary sources of Vitamin E, such as nuts, seeds, and vegetable oils, to ensure adequate intake.
While deficiency is uncommon, it can occur in patients with fat malabsorption disorders (e.g., cystic fibrosis, Crohn's disease), leading to neurological symptoms like peripheral neuropathy and ataxia due to oxidative nerve damage.
What if? If a patient presents with unexplained bruising and prolonged bleeding time, the nurse should consider a potential deficiency in Vitamin K, not Vitamin E, as Vitamin K is essential for the synthesis of clotting factors.

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: 'fat-soluble vitamins' and 'antioxidant function'.
Next, systematically recall the primary function of each vitamin listed in the options.
For Vitamin A, think 'vision'.
For Vitamin D, think 'calcium and bones'.
For Vitamin K, think 'clotting'.

Concept Tested & Keywords

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

Practise the full UPUMS Nsg officer-2023

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