Vitamin D is largely stored in the body in

Appeared in: NHM UP Staff Nurse-2021 Shift-1st

Explanation

Vitamin D is classified as a fat-soluble vitamin, along with vitamins A, E, and K.
Due to its fat-soluble nature, the body's primary and largest reservoir for storing excess Vitamin D is the adipose (fatty) tissue.
The liver also serves as a significant storage site, but fatty tissue holds the largest amount.
When the body requires Vitamin D, it is mobilized from these fat depots and released into the bloodstream for use.

Option A: While skeletal muscle does store some Vitamin D, it is considered a secondary storage site and does not hold the largest amount compared to fatty tissues.
Option C: The skin is the site of Vitamin D synthesis (production) through exposure to sunlight, not its primary storage location. 7-dehydrocholesterol in the skin is converted to cholecalciferol (Vitamin D3).
Option D: The gall bladder's role is to store and concentrate bile, which is then released into the small intestine to aid in the digestion and absorption of fats and fat-soluble vitamins. It does not store the vitamins themselves.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Storage of fat-soluble vitamins as background academic context rather than a clinical decision trigger.
Because Vitamin D is stored in fat, it is not readily excreted. This means that very high, prolonged doses of supplements can lead to toxicity (hypervitaminosis D), causing hypercalcemia.
In individuals with obesity, large amounts of Vitamin D can be sequestered (trapped) in the extensive adipose tissue, leading to lower circulating levels of the vitamin and a higher risk of functional deficiency.
Nurses should educate patients on safe sun exposure and the risks of over-supplementation without medical guidance, especially with fat-soluble vitamins.

How to Approach the Question

First, identify the key subject of the question, which is 'Vitamin D', and the key action, which is 'largely stored'.
Recall the fundamental classification of vitamins: are they water-soluble or fat-soluble? Vitamin D is fat-soluble.
Connect the property (fat-soluble) to the likely storage location. The body stores fat-soluble substances in its fat reserves.
Evaluate the given options based on this knowledge. 'Fatty tissues' is the most logical and direct answer.
Eliminate the other options by recalling their primary functions: Skin is for synthesis, the gall bladder is for aiding digestion, and muscles are only a minor storage site.

Concept Tested & Keywords

Q9klCjb9hc4zCbjXZDnpeW

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) p. 151-153

E6 Nutrition Monika Sharma 3e p. 130-132

Practise the full NHM UP Staff Nurse-2021 Shift-1st

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