Calcium Carbonate | whatsinit

About

What it is and where it shows up.

Calcium carbonate (CaCO3) is an inorganic mineral salt derived from ground limestone, chalk, or marble, authorized in food as a white colourant, acidity regulator, anti-caking agent, and calcium-fortification source. It is widely used in bakery products, confectionery, dietary supplements, and infant formulae.

Safety summary

The regulatory and scientific consensus.

EFSA (2023) concluded there is no need for a numerical ADI and no safety concern at current use levels across all population groups, including infants below 16 weeks of age. The ADI has been designated 'not specified' by both JECFA (1965) and EFSA (2011), reflecting a very low toxicological risk profile at food-additive intake levels. A minor concern noted by EFSA (2023) relates to the unavoidable presence of trace aluminium impurities in E170 preparations; additionally, high supplemental calcium intake above the established upper limit of 2,500 mg/day from all sources has been associated in meta-analyses with potential cardiovascular events.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	Authorised as food colour and acidity regulator under Regulation (EC) No 1333/2008, Annex II; ADI 'not specified'; most uses permitted at quantum satis. EFSA 2023 re-evaluation confirmed no safety concern across all age groups including infants below 16 weeks. Trace aluminium impurities flagged as a data gap requiring further specification amendment.source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Permitted as INS 170(i) under FSSAI Food Safety and Standards (Food Products Standards and Food Additives) Regulations, including as an ingredient in baking powder (Chapter 2.11) and other food categories.source
FDA (Food and Drug Administration) (United States)	Approved	GRAS under 21 CFR 184.1191; permitted as a miscellaneous ingredient, nutrient source, and emulsifying agent in bakery products (Part 136), frozen desserts (Part 135), dietary supplements (182.5191, 182.8191), and other foods at GMP levels. Also listed in Part 137 admixed with benzoyl peroxide for flour bleaching.source

Who should approach with care

Whose guidance would steer them away.

Kidney Disease — Patients with chronic kidney disease have impaired calcium homeostasis; while calcium carbonate is used clinically as a phosphate binder in CKD, unsupervised high intake from food and supplements can precipitate hypercalcaemia and worsen renal function.

Heart Disease — Meta-analyses cited in the EFSA 2023 opinion (Bolland et al.) have raised contested concerns that high supplemental calcium intake may be associated with increased cardiovascular event risk, though this applies primarily to high-dose supplement use rather than typical food-additive exposure levels.

Other — Individuals with hypercalcaemia or hyperparathyroidism should avoid additional calcium carbonate intake, as it can exacerbate elevated serum calcium levels; the SCF upper tolerable intake level for calcium from all sources is 2,500 mg/day.

Research citations

The sources behind this verdict.

1FDA. Food Additive Status List – Calcium Carbonate (21 CFR 184.1191). fda.gov
2FSSAI. FSSAI Food Safety and Standards – Chapter 2.11: Other Food Products and Ingredients (INS 170(i)). fssai.gov.in
3FSSAI. Food Safety and Standards (Food Products Standards and Food Additives) Regulations – Appendix C: Active List of Processing Aids (Version 2, August 2025), 2025. fssai.gov.in
4EFSA. Re-evaluation of calcium carbonate (E 170) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as food additive for uses in foods for all population groups, 2023. efsa.europa.eu
5PubMed. Re-evaluation of calcium carbonate (E 170) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as food additive for uses in foods for all population groups, 2023. pubmed.ncbi.nlm.nih.gov

Independently researched6 citations