Calcium
Affiliate link: we may earn a commission at no extra cost to you. Disclosures
Calcium. Major bone mineral; also critical for muscle contraction and nerve signaling.
How it works. Stored as hydroxyapatite in bone; cytosolic Ca²⁺ triggers muscle contraction and exocytosis.
What the research supports. 1 graded claims. Strongest: Reduces fracture risk with vitamin D in deficient elderly (moderate).
How much to take. Typical dose: 500–1000 mg from diet+supp combined. Split <500 mg per dose.
Side effects and interactions. 2 medication interactions listed. Serious: Possible CV risk with high-dose supplements (debated).
Stacking. Pairs well with A high-quality multivitamin, Omega-3 (EPA/DHA). Avoid combining with Iron (same dose).
Common forms. Available as Citrate (no acid required), Carbonate (cheap, needs acid), Hydroxyapatite.
Key studies. 8 studies cited. The strongest are listed with links to PubMed.
Community. Experiences from people who have tried Calcium. Anecdotes are not medical advice.
Calcium. Major bone mineral; also critical for muscle contraction and nerve signaling.
What it is
Major bone mineral; also critical for muscle contraction and nerve signaling.
Also called
Food sources
Goals
How it works
Stored as hydroxyapatite in bone; cytosolic Ca²⁺ triggers muscle contraction and exocytosis.
Pathways
- Bone mineralization
- Excitation-contraction coupling
Effects
- +Bone mineral density supports
What the research supports
Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.
As an Amazon Associate I earn from qualifying purchases. Look for USP, NSF or Informed Sport seals before you buy.
Side effects & interactions
Common side effects
- Constipation (carbonate)
Serious
- Possible CV risk with high-dose supplements (debated)
Medication interactions
Reduces absorption — separate 4 h.
Chelates antibiotic.
Check any supplement–medication combination with your pharmacist before starting.
Combines with
Pairs well
- A high-quality multivitaminCovers micronutrient cofactors that support most supplement pathways.
- Omega-3 (EPA/DHA)Foundational anti-inflammatory support that complements most regimens.
Avoid combining
- Iron (same dose)Mutual absorption inhibition.
Common forms
- Citrate (no acid required)
- Carbonate (cheap, needs acid)
- Hydroxyapatite
Key studies
8 studies cited in total.
Opens current human and preclinical literature matching Calcium and "Reduces fracture risk with vitamin D in deficient elderly". Filter by RCT, meta-analysis, or year on the results page.
Opens current human and preclinical literature matching Calcium and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.
Opens current human and preclinical literature matching Calcium and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.
Discussion
Loading discussion…