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Mineral

Calcium (Calcium Carbonate)

Also known as: calcium carbonate, cal carb, CaCO3

A
Evidence

An essential mineral required for bone health, muscle contraction, nerve transmission, and hormonal regulation. Calcium carbonate is an inexpensive, well-absorbed form commonly used in supplements.

Primary uses

  • Bone health and density
  • Muscle contraction
  • Nerve transmission
  • Cardiovascular health
  • Hormonal regulation
  • Osteoporosis prevention

How it works

  • Structural component of bone and teeth
  • Cofactor for muscle contraction proteins
  • Regulates neurotransmitter release
  • Modulates vascular tone
  • Supports parathyroid hormone signaling

Dosage

Typical range
1000-1200 mg daily for adults (adequate intake); up to 2000 mg daily tolerable upper limit
Timing
Divided doses improve absorption (max ~500 mg per dose)
With food
Calcium carbonate should be taken with food; calcium citrate does not require food
Duration
Safe for long-term use; lifelong intake critical for bone health
Special populations
Women over 50 require 1200 mg daily; men 51+ require 1000-1200 mg daily; postmenopausal women benefit from adequate intake combined with vitamin D

Forms

  • calcium carbonate· 70/100
  • calcium citrate· 70/100
  • calcium phosphate· 70/100
  • calcium lactate· 70/100

Safety

Common side effects

  • Constipation (common with calcium carbonate)
  • Bloating or gas
  • Hypercalcemia at very high intakes

Contraindications

  • Hypercalcemia or calcium metabolism disorders
  • History of kidney stones (high doses)
  • Severe kidney disease

Evidence notes

Extensive RCT evidence for bone health, fracture prevention, and cardiovascular effects. Strong evidence for supplementation efficacy, particularly in women over 50 and those at risk for osteoporosis.

Grade A: Multiple well-designed human trials support the main claims.

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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider.