Bones contains abundantly by which mineral?

Appeared in: MNS 2015

Explanation

Bones serve as the body's main reservoir for calcium, storing about 99% of the total body calcium.
Calcium is the most abundant mineral in the human body, with a total content of 1 to 1.5 kg in an adult.
It combines with phosphorus to form hydroxyapatite crystals, the inorganic compound that gives bones their hardness and strength.
The ratio of calcium to phosphorus in bone is approximately 2:1, making calcium the most plentiful mineral.

Option A: Iron's primary physiological role is as a central component of hemoglobin in red blood cells, responsible for oxygen transport. It is not a major structural mineral of bone.
Option C: Sodium is the primary cation in the extracellular fluid and is crucial for maintaining fluid balance, nerve transmission, and muscle function. It is not stored in large quantities within the bone matrix.
Option D: Although phosphorus is the second most abundant mineral in bone and is essential for forming hydroxyapatite, it is present in a lower quantity than calcium.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Composition of bone tissue and primary mineral content as background academic context rather than a clinical decision trigger.
Nurses monitor serum calcium levels as they can indicate bone health issues like osteoporosis or metabolic disorders. Hypocalcemia or hypercalcemia requires careful management.
Patient education on dietary sources of calcium (e.g., dairy, leafy greens) and Vitamin D (for absorption) is a key nursing role in preventing bone diseases.
What if? If a patient has chronic kidney disease, their ability to excrete phosphorus is impaired. This leads to high phosphate levels, which can pull calcium out of the bones, making them weak. The nursing priority shifts to managing phosphate levels through diet and phosphate binders.

How to Approach the Question

First, identify the core of the question: it asks for the most abundant mineral in bones.
Recall the basic composition of bone tissue. Remember that bones are the primary storage site for certain minerals.
Evaluate the options based on their main functions in the body.
Calcium is widely known for its role in bones and teeth. Phosphorus is also involved, but is it the most abundant?
Iron is related to blood, and sodium to fluid/nerve function. These are less likely to be the primary structural mineral of bone.
Conclude that calcium is the most abundant mineral, even though phosphorus is also a major component.

Concept Tested & Keywords

Q072vZ2hPXEbmLhTnvIO6a

E6 Biochemistry U Satyanarayana— Part 2 (pp 421-820 of 840) p. 21-23

E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) p. 297-299

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart A (pp 1-239 of 478) p. 159-161

Practise the full MNS 2015

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