Calcium Deficiency

Key facts

• Calcium deficiency, or hypocalcaemia, means blood calcium has fallen too low to support normal muscle contraction, nerve signalling and bone maintenance.
• Poor dietary intake is the most common cause; low vitamin D, malabsorption and an underactive parathyroid gland also contribute.
• Symptoms range from muscle cramps, tingling in the hands and feet, and fatigue, through to brittle nails and, over time, weakened bones tied to bone health.
• Calcium carbonate supplementation is the standard first step, alongside dietary sources and correcting any vitamin D shortfall; persistent cramps, numbness or an irregular heartbeat warrant a blood test.

What drives low calcium

Poor dietary intake is the most frequent cause, but deficiency can also stem from low vitamin D, malabsorption, or an underactive parathyroid gland. Diets low in dairy and limited sun exposure, which the body needs to make the vitamin D that drives calcium absorption, are common contributors. Symptoms range from muscle cramps, tingling in the hands and feet, and fatigue, through to brittle nails and, over time, weakened bones under the umbrella of bone health conditions.

How it is corrected

Supplementation with calcium carbonate is the standard first step: it delivers a high elemental calcium content per tablet and is best absorbed when taken with food. Alongside supplementation, boosting dietary sources, milk, tofu, leafy greens and fortified foods, and addressing any underlying vitamin D shortfall are equally important.

When to get tested

Persistent cramps, numbness, or an irregular heartbeat alongside suspected low calcium warrant a blood test to confirm the diagnosis and rule out other causes. A doctor can also check vitamin D and parathyroid hormone levels, since correcting those underlying drivers matters as much as the calcium level itself.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.