Mineral

Calcium (Calcium Carbonate)

Also known as: calcium carbonate, cal carb, CaCO3

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.

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Daily target & upper limit

1300 mg / day · UL 2500 mg

Calcium (Calcium Carbonate) has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:

Calcium (Calcium Carbonate) dosage reference →

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

Products containing Calcium (Calcium Carbonate)

Top-scoring supplements in our catalog that list Calcium (Calcium Carbonate) on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.

Thorne

Protein Isolate - Chocolate

Transparent Labs

Grass-Fed Whey Protein Isolate

Thorne

Whey Protein Isolate - Vanilla

Nutricost

Calcium + Vitamin D3 Tablets

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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.