Which of the following vitamins increases calcium absorption in the gastrointestinal tract?

Bihar CHO - 2021

Applied Nutrition & Dietetics

Easy

Appeared in: Bihar CHO - 2021

Explanation

Vitamin D is the key hormone responsible for increasing calcium absorption from the small intestine.
Its active form, calcitriol, promotes the synthesis of calcium-binding proteins (calbindin) in intestinal cells, which facilitates calcium transport into the blood.
This function is critical for normal bone mineralization and preventing conditions like rickets and osteomalacia.
Vitamin D works in concert with parathyroid hormone (PTH) and calcitonin to maintain calcium homeostasis.

Option A: Vitamin C is primarily known for enhancing the absorption of non-heme iron, not calcium. Its main roles are as an antioxidant and in collagen synthesis for wound healing.
Option C: Vitamin E's primary role is as a fat-soluble antioxidant, protecting cell membranes from oxidative damage. It does not have a direct or significant role in calcium absorption.
Option D: Vitamin A is crucial for vision (as a component of rhodopsin), immune function, and maintaining epithelial tissues. It is not involved in regulating calcium absorption.

Clinical Relevance

Nursing practice connection: Knowing Role of vitamins in mineral absorption helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses educate patients on the importance of adequate Vitamin D for bone health, especially in at-risk populations like the elderly, breastfed infants, and individuals with limited sun exposure.
Understanding the link between Vitamin D, calcium, and bone disease is crucial for managing patients with osteoporosis, renal failure, and hypoparathyroidism.
What if? If a patient has chronic kidney disease, they may be unable to convert Vitamin D to its active form (calcitriol). In this case, simply supplementing with standard Vitamin D (cholecalciferol) would be ineffective. The patient would require a prescription for an active form like calcitriol to manage hypocalcemia.

How to Approach the Question

First, read the question carefully to identify the core concept: which vitamin affects calcium absorption in the GI tract.
Recall the primary functions of the major vitamins listed in the options (A, C, D, E).
Associate Vitamin D with its well-known role in bone health and calcium regulation. Remember the mnemonic 'Vitamin D for bones' or its link to sunlight.
Consider the function of the other vitamins. Vitamin C is linked to iron absorption and scurvy. Vitamin A is linked to vision. Vitamin E is an antioxidant.
Based on this knowledge, identify Vitamin D as the only option directly responsible for increasing intestinal calcium absorption.
Confirm the choice by eliminating the other options based on their primary physiological roles.

Concept Tested & Keywords

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