Calcium

How much do you need daily?

Adults need 700 milligrams of calcium per day. You should be able to get all the calcium you need from your daily diet.

Are we getting enough?

The 2017 National Diet and Nutrition Survey found that average daily intakes of calcium from food were above the recommended level for most people except teenagers aged 11 to 18 years (for whom average intakes were 84 to 89 per cent of the recommended amount for girls and boys respectively). Furthermore, among teenagers and women, a large number are falling short of the target (19 per cent of girls and eight per cent of boys aged 11 to 18 years, and eight per cent of women aged 19 to 64).

Why do we need it?

We associate calcium with bones and rightly so. But calcium has other functions too – it’s important for muscle function, nerve transmission, signalling within cells and hormone formation.

Calcium is a building block for bones and they contain 99 per cent of the total calcium in your body. But calcium can only build bones properly if your body has enough vitamin D. So even if you eat plenty of calcium, it could go to waste if you don’t get enough vitamin D.

Our bodies continually remove small amounts of calcium from our bones (which act as calcium reservoirs) and replace it with new calcium. This is called bone remodelling, whereby calcium is removed from the skeleton (bone resorption) and new bone tissue is formed (ossification).  

Therefore, we need a regular, sufficient intake of calcium but it’s highly questionable whether calcium intakes above the minimum amount required by the body can offer any benefit at all. Indeed, excessive calcium intakes (from dairy products and supplements), can even increase the risk of fractures and some of the calcium may be deposited in other tissues (eg kidneys) which can eventually cause problems such as kidney stones. Once intake surpasses 2,000 milligrams per day, the risk of harm increases.

Do I need a supplement?

No, a healthy vegan diet containing the foods listed below on a daily basis will cover your needs.

The best plant sources

The best plant sources of calcium are: tofu (made with calcium sulphate), fortified vegan breakfast cereal (Ready Brek), plant-based milk alternatives fortified with calcium, dried figs, kale, sesame seeds and tahini (sesame seed paste), tempeh (fermented soya beans), wholemeal bread, baked beans, butternut squash, almonds and Brazil nuts, spring greens and watercress.

While spinach, chard and beet greens contains a relatively high amount of calcium, they also contain a substance called oxalate which hinders calcium absorption. It is better to obtain calcium from low-oxalate green vegetables like kale, broccoli and bok choy. The calcium in these is absorbed about twice as well as the calcium in milk. They also contain fibre, folate, iron and antioxidants, some of the very nutrients lacking in dairy.

Signs of deficiency

muscle spasms or cramps, confusion, fainting, numbness and tingling in hands, feet and face, brittle nails, fragile bones, tooth decay and tiredness.