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E345 · Acidity regulators

Magnesium citrate

No known risk

A safe, functional magnesium supplement.

Category
Acidity regulators
Vegan
Yes
Vegetarian
Yes

What it is

A broad term for magnesium salts of citric acid (including E345(i)), widely used as a dietary supplement.

How it is used in food

Magnesium citrate combines high water solubility with good absorption, making it both an effective acidity regulator and one of the better-absorbed magnesium salts for fortification and supplements. The citrate keeps the magnesium in solution through the stomach and into the small intestine, where uptake occurs, so less is wasted than with poorly soluble oxide forms.

Commonly found in
  • Supplements
  • Laxatives
  • Beverages

Health and safety

Very safe, though high doses are used medicinally as a laxative.

Citric acid and citrates carry an ADI "not specified" from JECFA, and magnesium citrate is an authorised magnesium source in EU fortified foods and supplements. Comparative absorption studies place citrate among the more bioavailable magnesium salts, well ahead of magnesium oxide. Supplemental magnesium above roughly 250 mg/day reliably causes loose stools.

Regulatory status

RegionStatusNotes
Australia & New Zealand
FSANZ
Permitted Permitted under the FSANZ Food Standards Code.
European Union
EFSA / European Commission
Not approved Not on the EU authorised list of food additives (Annex II).
United States
FDA (Food and Drug Administration)
Permitted Authorised for food use by the FDA (often GRAS for standard additives).

Identification on labels

E-number
E345

Worth knowing

The same solubility that aids absorption becomes a deliberate side effect at higher doses: gram quantities of magnesium citrate are the basis of standard osmotic laxatives and colonoscopy bowel preparations.

Conclusion

A safe, functional magnesium supplement.

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Entry last reviewed 2026-07-28.

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