Magnesium

What it does

Magnesium is a quiet workhorse involved in more than three hundred enzyme reactions in the body. Many of these are tied to energy: magnesium is required to stabilise and use ATP, the molecule that stores and delivers energy in every cell, so effectively no energy-using process happens properly without it. This alone makes it fundamental to how the whole body works.

It has a particularly important role in muscles and nerves, where it helps regulate the flow of calcium and other minerals in and out of cells. This balance controls how muscles contract and relax and how nerves fire, which is why magnesium is important for a steady heartbeat, normal blood pressure and preventing cramps. It also contributes to building bone, alongside calcium and phosphorus, and to keeping blood sugar regulation working smoothly.

Magnesium is found in wholegrains, nuts, seeds, pulses and green leafy vegetables — its presence in chlorophyll means dark greens are a reliable source. Much of the body's magnesium is stored in bone and inside cells rather than in the blood, so a normal blood test does not rule out a shortfall. Diets high in refined and processed foods tend to be lower in magnesium than diets rich in wholefoods.