VitaminWell-studiedMineral

Calcium Carbonate

Also known as Calcium

Half-life

Bone turnover: ~10 years

What is Calcium Carbonate?

Most concentrated calcium form (40% elemental calcium). Requires stomach acid — take with food. Less expensive.

How Calcium Carbonate works

Disassociates in acidic gastric environment to provide free calcium ions for intestinal absorption via active transport (vitamin D-dependent) and passive diffusion.

Benefits & uses

Bone density support
Muscle/nerve function

Common uses: Bone density, osteoporosis prevention, acid neutralization (antacid use).

Longevity

Calcium Carbonate dosage

Typical dose: 500 mg per dose with meals. Total 1000–1200 mg/day from food + supplements combined.

Calcium Carbonate half-life

Bone turnover: ~10 years; plasma: rapid equilibration

Calcium Carbonate side effects

Constipation. Reduced absorption without stomach acid (avoid in those taking PPIs).

Constipation (more so than calcium citrate)
Gas and bloating
Requires stomach acid — do not take with PPIs
High intakes increase cardiovascular event risk in some studies — do not over-supplement
Constipation
Bloating

Warnings & monitoring

Pair with K2/D3 so calcium goes to bone; avoid excessive supplemental calcium

Commonly stacked with

Vitamin D3 Vitamin K2 MK-4

Track Calcium Carbonate in Protokol.

Log doses, model half-lives, check interactions, and line it all up against your bloodwork. Free on iPhone and Android.