Magnesium citrate

A mineral salt of magnesium and citric acid used in foods and supplements to supply magnesium and to regulate acidity; in higher doses it works as an osmotic laxative.

Should I eat Magnesium citrate?

A refined mineral salt that safely supplies magnesium at typical amounts but can act as a laxative at higher doses. Most people can use it without issue if they watch the dose and seek medical advice for kidney problems.

Summary

Magnesium citrate is widely used to add magnesium and regulate acidity, with Codex recognition and EU authorization (E 345(i)) for certain supplement formats. EFSA’s review found no safety concern at proposed use levels, and JECFA did not set a numeric ADI, indicating low toxicity at expected intakes. The main practical issue is dose: the NIH sets a 350 mg/day supplemental upper limit to minimize GI upset, and the ingredient is an FDA-recognized OTC laxative at higher amounts. Manufacturing involves neutralization and crystallization—not hydrogenation—so risks are primarily from overuse rather than processing.

Key Research Points

High doses can trigger diarrhea

Magnesium citrate draws water into the gut; intakes above the adult supplemental upper limit (350 mg/day elemental magnesium) commonly cause loose stools or cramping, and it is sold as an OTC laxative.

Kidney disease raises safety risks

If kidneys do not clear magnesium well, blood levels can build up (hypermagnesemia), so people with renal impairment should only use magnesium citrate with medical guidance.

Follow laxative labels to avoid imbalances

Overusing magnesium citrate laxatives can disturb fluids and electrolytes; use only as directed and maintain hydration.

Overview

What is it?

Source: Citric acid and magnesium salts

Method: Neutralization and crystallization

Processing Level: 7 / 10

Why is it used?

Purpose: Mineral salt used to supply magnesium and regulate acidity.

Commonly found in: protein bars;electrolyte powders;sports drinks;meal replacements;capsules

Why manufacturers choose it: Good solubility, decent absorption, and precise dosing.

Origin

Citrate chemistry dates to the isolation of citric acid from lemon juice in the 1700s. Bottled “citrate of magnesia” laxatives were common in U.S. pharmacies by the early 1900s, and magnesium citrate remains an OTC laxative today. In foods and supplements, manufacturers typically make it by reacting food-grade citric acid with magnesium oxide, hydroxide, or carbonate, then crystallizing and drying the salt.

Process: Neutralization and crystallization

Steps

1. Dissolve: Dissolve food-grade citric acid in purified water and heat.

2. Neutralize: Add magnesium oxide/hydroxide/carbonate slurry; control pH during reaction.

3. Crystallize: Cool, allow magnesium citrate to crystallize from solution.

4. Wash & Dry: Wash crystals; dry to the desired hydrate or anhydrous form; mill and sieve.

Chemicals

Citric acid

Magnesium oxide or hydroxide or carbonate

Water

Acetic acid (occasionally used in process controls per patents)

Research & Safety

Potential Concerns

Most people tolerate typical amounts, but higher intakes can cause loose stools, cramping, or diarrhea. Because it is also an OTC laxative, frequent or heavy use can disturb fluid and electrolyte balance; follow labeled directions and drink fluids. People with reduced kidney function can accumulate magnesium and should avoid unsupervised use. Processing-wise, magnesium citrate is a refined mineral salt produced by neutralizing citric acid and crystallizing the salt; it is not hydrogenated and does not introduce trans fats. Current safety reviews indicate the main concern is dose, not processing-related hazards.

Potential Benefits

Magnesium is essential for nerve signaling, muscle contraction, energy metabolism, and bone health. Magnesium citrate dissolves well and is generally absorbed better than some other forms, helping people meet daily needs when diet falls short. In foods and supplements, it provides a predictable amount of elemental magnesium per serving, supporting accurate labeling and claims. Its acidity‑regulating role supports taste and stability but does not add additional health effects beyond supplying magnesium.

Digestive Effects

Supplemental magnesium has a U.S. tolerable upper intake level of 350 mg/day for adults (this excludes magnesium naturally present in foods). Above this, magnesium citrate often causes soft stools or diarrhea because it pulls water into the bowel. Sensitive individuals, including some with IBS, may experience these effects at lower doses. When used as a laxative, follow label directions and maintain hydration to reduce cramping and fluid losses.

Limit Consumption

People with kidney disease or on dialysis should not use magnesium citrate without medical supervision due to the risk of hypermagnesemia. Those who are pregnant or breastfeeding can generally use supplemental magnesium within recommended limits, but it is wise to consult a clinician about dose and timing. Magnesium can interfere with the absorption of certain medications (for example, some antibiotics and thyroid or osteoporosis drugs); take them at different times as advised by a healthcare provider. For infants and young children, do not give magnesium citrate as a laxative or supplement unless directed by a clinician.

Fact Sheet

Regulatory Status

US FDA: Multiple magnesium salts are affirmed GRAS (21 CFR Part 184); magnesium citrate is an approved OTC laxative active and appears in FDA inventories. Direct GRAS section does not list magnesium citrate specifically by section, but it is widely used as a nutrient salt and OTC drug ingredient.

EU Status: E 345(i) trimagnesium dicitrate authorized as stabilizer/anticaking in solid/chewable food supplements (2024). Other uses as magnesium sources governed under nutrition rules.

Codex INS: 345

JECFA ADI: No ADI allocated (JECFA 29th meeting).

ESG & Sustainability

Environmental Footprint: Produced via aqueous neutralization and crystallization; low solvent use and relatively modest energy beyond drying; upstream impacts tied to citric acid fermentation and magnesium salt sourcing.

Sustainability: Citric acid is made by industrial fermentation; magnesium salts sourced from mined or brine-derived materials; overall footprint depends on supplier energy mix.

Animal Welfare: Mineral ingredient; no inherent animal welfare issues.

Carbon Footprint: Not well characterized publicly; dominated by fermentation, drying, and transport.