Which mineral is described as supporting cardiac function?

• A. Calcium
• B. Potassium
• C. Magnesium
• D. Iron

Answer: (C)

Magnesium helps maintain normal heart rhythm and supports cardiac function by stabilizing the electrical activity of heart muscle. It modulates ion flow and acts as a natural calcium antagonist, helping regulate calcium entry into cardiac cells and supporting the Na+/K+-ATPase pump to keep cell membranes less excitable. When magnesium is low, the heart is more prone to rhythm disturbances, so having adequate magnesium helps prevent arrhythmias and maintains steady cardiac conduction. While calcium is essential for contraction and potassium is crucial for electrical resting potential, magnesium’s specific role in dampening excitability and stabilizing rhythm makes it the mineral most closely associated with supporting cardiac function. Iron supports oxygen transport rather than direct electrical or rhythmic function of the heart.