Calcium is one of the most abundant minerals in the body, accounting for about 1.5 per cent of our total body weight.

It’s best known for its role in maintaining healthy bones and teeth, but calcium is also vital for regulating heart function, blood clotting, nerve conduction and muscle contraction and enzyme function.

When dietary intake of calcium is too low, the body will draw on the mineral in the bones to maintain normal levels in the blood. If this goes on for many years, osteoporosis can occur.

A condition called hypochlorhydria, which is characterised by the insufficient secretion of stomach acid, can impair the body’s ability to absorb calcium and other nutrients, and can occur in elderly people who are already at risk of osteoporosis.

Certain nutrients affect how efficiently calcium is absorbed into the body.

• Vitamin D, which is produced when our skin is exposed to sunlight, enhances calcium absorption.

• High levels of sodium, caffeine or protein cause increased excretion of calcium via urine.

• Too much fibre pushes food through the gut too quickly and limits the amount of time the body has to absorb calcium from food.

One important thing to note is that calcium in food and supplement form will impair the absorption of iron, which can affect women who take prescribed iron tablets.

If you’re currently on iron supplements and are considering taking calcium in a supplement form, see your GP before you start on any course. For those who don’t like milk products or can’t tolerate dairy, there are other ways you can increase your calcium levels. Try these:

• Tofu

• Orange juice (fortified with calcium)

• Soy milk (fortified with calcium)

• Almonds

• Canned salmon or sardines (including bones)

• Tahini (a sesame seed paste that’s used in making hummus)