Medicines for Low calcium (hypocalcaemia)

What it is

Hypocalcaemia means a lower-than-normal level of calcium in the blood. Because calcium is essential for nerve and muscle function, low levels tend to cause symptoms related to nerves and muscles becoming over-excitable: tingling or numbness (often around the mouth, and in the fingers and toes), muscle cramps, twitching, and, if severe, muscle spasms (including of the hands and, rarely, the voice box) and, in extreme cases, fits or heart-rhythm problems. Mild hypocalcaemia may cause few or no symptoms and be found on a blood test. Common causes include vitamin D deficiency (vitamin D is needed to absorb calcium), an underactive parathyroid gland (hypoparathyroidism, sometimes after thyroid or neck surgery), kidney problems, low magnesium, and some medicines. Because the causes are usually identifiable and treatable, and because significant hypocalcaemia can cause troublesome or dangerous symptoms, low calcium is assessed to find the cause and corrected.

How it is treated

Management involves correcting the calcium level appropriately and treating the underlying cause. A doctor will confirm the low calcium, and arrange tests to find the cause — including checking vitamin D, parathyroid hormone, kidney function, and magnesium. Treatment depends on the cause and severity: mild hypocalcaemia is often treated by addressing the cause (for example correcting vitamin D deficiency, treating low magnesium, or managing a parathyroid problem, sometimes with calcium and active vitamin D preparations), while more significant or symptomatic hypocalcaemia may need calcium supplementation, and severe hypocalcaemia (with marked symptoms such as spasms, fits, or heart effects) is a medical emergency needing urgent treatment with calcium given into a vein in hospital. Where hypocalcaemia is ongoing (for example due to hypoparathyroidism), long-term treatment and monitoring with calcium and vitamin D preparations keep the level stable. The reassuring message is that hypocalcaemia is usually treatable once the cause is found — often low vitamin D or a parathyroid problem — with severe cases treated urgently and ongoing causes managed with long-term supplementation and monitoring.