Calcium
Calcium is the most abundant mineral in the body, and about 99 per cent of it is stored in bones and teeth. It is indispensable for muscle contraction and nerve conduction as well.
| Type | Mineral (macromineral) |
|---|---|
| Main roles |
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| Sources |
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| Deficiency note | Inadequate intake over the long term is associated with a fall in bone density; the measurement and assessment of bone health are carried out at a health service. |
| Caution | The risks of high-dose supplements are debated and they can interact with some medicines; the need should be assessed together with a doctor. |
The bone bank analogy
Bones work like a store of calcium: if intake is adequate the store is preserved, and if it is not the body draws on bone to keep the level of calcium in the blood steady. Building a strong "bone bank" in the younger years is valuable for offsetting the loss of bone later in life. Calcium is needed not only for bone but also for muscle contraction, nerve conduction and the clotting of blood.
Sources and the partnership with vitamin D
The best-known sources are milk, yoghurt and cheese; sesame and tahini, almonds, small fish eaten with their bones, dark green leafy vegetables and fortified products contribute as well. The critical point is this: vitamin D is needed for calcium to be absorbed from the gut, and without one the other cannot do its job fully. Requirements vary with age; growth, pregnancy and the years after the menopause are the periods when the need rises.
Does everyone need a supplement?
No; the priority is always intake from food. For people who cannot eat dairy products, lactose-free products, fortified drinks and calcium-rich plant sources offer options. The link between high-dose calcium supplements and the risk of kidney stones is a debated subject, and they can also affect the absorption of some medicines. Whether a supplement is needed should be determined by a doctor, alongside an assessment of age, pattern of eating and bone health.
Related terms: Vitamin D, Magnesium, Milk, Yoghurt