Micronutrient Deficiency—Identify the Mineral Which mineral deficiency most commonly leads to impaired growth and development, characteristic skin lesions (dermatitis), and reduced appetite in humans?

Introduction / Context:
Zinc is an essential trace element required for hundreds of enzymes and numerous transcription factors. Its deficiency presents with a recognizable triad in clinical nutrition: growth retardation, dermatitis or periorificial skin lesions, and anorexia (loss of appetite). This question tests recognition of that classic pattern and differentiates zinc deficiency from other trace mineral problems.

Given Data / Assumptions:

• Symptoms listed: impaired growth and development, skin lesions, and loss of appetite.
• Population context: could be children, adolescents, or malnourished adults; risk is higher with low dietary zinc or malabsorption.
• No confounding conditions are specified (e.g., acrodermatitis enteropathica), but the symptom cluster is typical of zinc lack.

Concept / Approach:
Zinc functions as a catalytic, structural, and regulatory cofactor. Deficiency impairs DNA synthesis and cell division, explaining poor growth. It also disrupts epithelial integrity and immune function, causing dermatitis and higher infection risk, and alters taste/smell and appetite regulation, causing anorexia. Iron, magnesium, cobalt, or selenium deficiencies present differently and do not match the full triad as specifically as zinc deficiency does.

Step-by-Step Solution:

Verification / Alternative check:
Clinical improvement after zinc supplementation (e.g., 10–20 mg elemental zinc/day in deficient children) rapidly restores appetite and accelerates growth, confirming causal linkage.

Why Other Options Are Wrong:

• Cobalt: mainly relevant to vitamin B12; cobalt deficiency per se is not the classic cause of these symptoms in humans.
• Iron: deficiency causes microcytic anemia, fatigue, pallor; skin lesions and appetite loss are not the hallmark triad.
• Magnesium: neuromuscular irritability, cramps, arrhythmias; not a classic cause of growth failure with dermatitis.
• Selenium: cardiomyopathy or thyroid issues; not the described triad.

Common Pitfalls:
Confusing general malnutrition with a specific micronutrient deficiency; overlooking zinc’s role in taste—patients may report food “tastes off,” contributing to anorexia.

Final Answer:
Zinc