What does it do?
Most calcium is stored in bones and teeth. It also helps muscles move, nerves transmit signals and blood vessels function.
Where can I get it in food?
Yogurt, milk, fortified beverages, calcium-set tofu, canned fish with bones and certain greens.
When might a supplement make sense?
A supplement may help when dietary intake is below individual needs. Vitamin D is important for calcium absorption; the two nutrients work together, but that does not mean everyone needs both in pill form.
What should I be careful about?
Supplement research on fracture prevention is mixed. Large doses can raise risks and may interfere with some medications; discuss the appropriate total intake with a healthcare professional.
How does this connect with Blue Zones?
Traditional diets vary between the Blue Zone regions. Rather than copying one food, consider the whole diet for calcium, vitamin D and protein alongside weight-bearing movement.
Read the original evidence
NIH Office of Dietary Supplements — Calcium fact sheet ↗
Educational information only. This primer explains nutrient biology; it does not promise longevity or offer personalized medical advice. Last reviewed for source alignment: November 2026. Editorial review recommended before publication.