Muscle twitching, restlessness, and convulsions are signs of deficiency of which mineral?

• A. Calcium deficiency
• B. Magnesium deficiency
• C. Vitamin D deficiency
• D. Iron deficiency

Answer: (A)

Calcium is essential for stabilizing nerve membranes and triggering muscle contraction at the neuromuscular junction. When calcium levels drop, nerves and muscles become more easily excited, so you see increased neuromuscular activity. That heightened excitability shows up as muscle twitching, restlessness, and, in more severe cases, convulsions. These signs are classic for low calcium (hypocalcemia) because calcium normally dampens excitability and helps regulate neurotransmitter release.

Magnesium deficiency can cause neuromuscular irritability as well, but the pattern isn’t as specific to the twitching and convulsions described. Vitamin D deficiency affects calcium metabolism and bone health more broadly and isn’t as directly tied to acute neuromuscular signs. Iron deficiency leads primarily to anemia-related symptoms like fatigue and pallor, not these neuromuscular symptoms.