Calcium Supplements

Calcium is the most abundant mineral in the body, with around 99% stored in bones and teeth. It also contributes to normal muscle function, normal nerve signalling and normal blood clotting — all authorised nutrition claims in the UK. While dairy products are the most widely known dietary source, many people supplement calcium due to dairy-free diets, increased requirements during certain life stages, or simply as part of a broader bone health routine.

This collection includes calcium carbonate, calcium citrate, and combination products pairing calcium with vitamin D, magnesium or both, in tablet, capsule and chewable formats.

Understanding Elemental Calcium — The Number That Actually Matters

Like magnesium and vitamin D, calcium labels can be confusing. The key figure to compare is elemental calcium — the actual amount of calcium your body can absorb per serving — not the total compound weight.

• Calcium carbonate contains around 40% elemental calcium by weight — a higher proportion, which is why it appears in many products and is generally more cost-effective
• Calcium citrate contains around 21% elemental calcium by weight, meaning you typically need more tablets to reach the same dose — but it is absorbed without needing stomach acid, making it easier to take at any time of day

Most adults in the UK are recommended to aim for 700mg of elemental calcium daily from all sources combined (diet and supplements). Because calcium absorption is more efficient in smaller amounts, splitting your daily supplement dose is generally preferable to taking it all at once.

For guidance on which form suits different needs and how to take calcium alongside vitamin D and magnesium, see the FAQs below.