Which of the vitamin is regarded as kidney hormone?

NVS- 2025

Applied Nutrition & Dietetics

Easy

Appeared in: NVS- 2025

Explanation

Vitamin D is unique among vitamins because it functions as a prohormone, meaning it is a precursor to a hormone.
It undergoes a final, critical activation step in the kidneys, where it is converted into its biologically active form, calcitriol (1,25-dihydroxycholecalciferol).
This active form, calcitriol, then functions as a true hormone, circulating in the bloodstream to regulate calcium and phosphate homeostasis by acting on the intestines, bones, and kidneys.

Option B: Thiamine (Vitamin B1) is a water-soluble vitamin that acts as a coenzyme (thiamine pyrophosphate) in carbohydrate metabolism and is essential for nerve function. It does not have a hormonal role.
Option C: Vitamin K is a fat-soluble vitamin whose primary role is to act as a coenzyme in the liver for the synthesis of blood coagulation factors (II, VII, IX, and X). It is not a hormone produced by the kidney.
Option D: Vitamin C (ascorbic acid) is a water-soluble vitamin that functions as an important antioxidant and is a cofactor for enzymes involved in collagen synthesis and wound healing. It does not function as a hormone.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Hormonal function of Vitamin D and the role of the kidneys in its activation as background academic context rather than a clinical decision trigger.
In patients with Chronic Kidney Disease (CKD), the kidneys' ability to activate Vitamin D is impaired. This leads to low calcitriol levels, causing hypocalcemia, secondary hyperparathyroidism, and renal osteodystrophy (a type of bone disease).
Nurses play a key role in monitoring serum calcium, phosphorus, and parathyroid hormone (PTH) levels in CKD patients and administering prescribed active Vitamin D analogs like calcitriol.
What if? If a patient has severe liver disease instead of kidney disease, the first step of Vitamin D activation (conversion to 25-hydroxycholecalciferol) would be impaired. This would also lead to a deficiency of active Vitamin D, even with adequate sun exposure or dietary intake.

How to Approach the Question

First, identify the keywords in the question stem: 'vitamin' and 'kidney hormone'.
This is a factual recall question that requires knowledge of the specific metabolic pathways and functions of different vitamins.
Systematically review the primary function of each vitamin listed in the options.
Recall that Vitamin D is unique in that it can be synthesized in the skin and requires activation in the body to function.
Remember that the final, rate-limiting step of Vitamin D activation occurs in the kidney, which converts it into a hormone (calcitriol) that regulates calcium.
This direct link between the kidney and the production of the active hormone makes Vitamin D the correct answer.

Concept Tested & Keywords

Concept Tested: Hormonal function of Vitamin D and the role of the kidneys in its activation.
Stem keywords: vitamin, kidney hormone
Lead-in keywords: Which
Negative lead-in flag: false

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

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