Step 1: Understanding the Question.
The question asks which mineral, when it runs low in the body, leads to anaemia.
Step 2: Key Concept.
Anaemia is a condition where the blood has too few healthy red blood cells or too little hemoglobin, so the blood cannot carry enough oxygen around the body. Hemoglobin is built using iron, so a shortage of iron directly cuts down how much hemoglobin the body can make.
Step 3: Detailed Explanation.
When iron intake is too low, or when the body loses iron faster than it takes it in, such as through heavy bleeding, the bone marrow cannot make enough hemoglobin. This leads to smaller, paler red blood cells and the tiredness, weakness, and pale skin seen in anaemia.
Iodine deficiency affects the thyroid gland and causes goitre, not anaemia.
Calcium deficiency affects bones and teeth and can cause weak bones, not anaemia.
Zinc deficiency affects growth, wound healing, and immunity, but it is not the main cause of anaemia.
Step 4: Final Answer.
Anaemia is caused due to deficiency of iron, so option (C) is correct.