Calcium — Supplements
Essential mineral for bone health, muscle contraction, and nerve signaling.
Overview
Calcium is the most abundant mineral in the body, with 99% stored in bones and teeth as hydroxyapatite. Adequate calcium intake is essential for bone mineral density maintenance, particularly in postmenopausal women and older adults. Calcium also plays critical roles in muscle contraction, nerve impulse transmission, blood coagulation, and intracellular signaling. Strong evidence supports calcium supplementation (with vitamin D) for fracture risk reduction in deficient populations, though recent guidelines emphasize food-first approaches.
Indications
- Osteoporosis prevention and management
- Bone mineral density preservation
- Muscle and nerve function support
- Dietary calcium insufficiency
Mechanism of Action
Calcium combines with phosphate to form hydroxyapatite crystals in the bone matrix
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Calcium | 500 mg | 1-2 times daily | Take with vitamin D for enhanced absorption; split doses for optimal uptake |
Evidence Grade
GRADE C
Safety & Contraindications
- Do not exceed 500 mg per dose for optimal absorption
- Cardiovascular concerns with high-dose supplementation (>1,000 mg/day) debated
- May cause constipation and GI discomfort
- Calcium carbonate requires gastric acid; take with food. Calcium citrate can be taken without food
- May reduce absorption of thyroid medications, bisphosphonates, and certain antibiotics