What is E578?

Complete guide to understanding E578 (Calcium Gluconate) in your food

The Quick Answer

E578 is calcium gluconate, an organic mineral salt made from gluconic acid (a naturally occurring compound derived from glucose) bonded with calcium.

It’s used in food as a stabilizer, firming agent, thickener, acidity regulator, and calcium fortifier—providing both functional benefits and nutritional value.

Unlike many other E-numbers that are controversial, calcium gluconate is valued for being both safe and nutritious, making it particularly popular in health-conscious food products.

What Exactly Is It?

E578 is the calcium salt of gluconic acid.

Gluconic acid is a naturally occurring organic acid created by oxidizing glucose. When gluconic acid is chemically bonded with calcium, it creates calcium gluconate—a white crystalline compound that dissolves in water.

This is fundamentally different from most food additives: E578 doesn’t just provide function (stabilization, thickening); it also provides genuine nutritional value by supplying bioavailable calcium.

Chemical formula: C₁₂H₂₂CaO₁₄ or Ca(C₆H₁₁O₇)₂

How it’s made:

Three commercial production methods exist:

• Fermentation (most common modern method): Specific bacterial strains ferment glucose in a controlled medium to produce gluconic acid, which is then neutralized with calcium to create the salt
• Chemical oxidation: Glucose is oxidized using hypochlorite (bleach) solution to create gluconic acid
• Electrolytic oxidation: A glucose solution containing bromide is electrochemically oxidized to produce gluconic acid

Historical context: Calcium gluconate came into medical use in the 1920s and remains on the World Health Organization’s List of Essential Medicines—a testament to its safety and utility.

Where You’ll Find It

E578 appears in a wide range of food products:

• Beverages (sports drinks, fortified drinks, instant preparations)
• Dairy products (yogurt, milk, cheese alternatives)
• Puddings and custards (powder mixes)
• Canned vegetables
• Baked goods
• Instant preparations
• Low-temperature processed products
• Clear and concentrated beverages
• In-line blended products
• Breakfast cereals (fortified varieties)
• Bone broth and gelatin products
• Nutritional supplements and fortified foods
• Plant-based milk alternatives
• Bakery fillings and icings

E578 is particularly common in health-conscious products and foods marketed for bone health, calcium fortification, or nutritional enhancement.

Why Do Food Companies Use It?

E578’s primary function is stabilization, firming, and calcium fortification.

Food manufacturers use calcium gluconate for multiple advantages:

• Calcium fortification: Adds bioavailable calcium to foods—genuine nutritional benefit
• Stabilization: Prevents ingredient separation and settling in complex formulations
• Firming agent: Strengthens structure of canned vegetables and cooked products
• Water binding: Retains moisture and improves texture
• pH regulation: Adjusts and stabilizes acidity (functions as acidity regulator)
• Thickening: Increases viscosity and body without affecting flavor
• Sequestrant: Binds metal ions that could cause discoloration or rancidity
• Anti-caking agent: Prevents powder products from clumping
• Chelating agent: Removes unwanted minerals that might interfere with color or stability
• Flavor modulation: Can mask off-flavors in fortified products
• Cold solubility: Remains soluble at low temperatures—important for ice cream, frozen products, and instant preparations
• Clean label advantage: E578 can often be labeled simply as “calcium” or “calcium gluconate,” making it attractive for “natural” marketing

Unlike many food additives that are purely functional, E578 combines functionality with nutritional benefit—making it a “win-win” for both manufacturers and health-conscious consumers.

Is It Safe?

E578 is one of the safest food additives approved for use.

Approval status:

• FDA approved: Listed as GRAS (Generally Recognized As Safe) under 21 CFR §184.1199
• EFSA approved: Listed as generally permitted food additive in EU (Regulation EC 1333/2008)
• WHO approved: On WHO’s List of Essential Medicines
• International approval: Approved in virtually all countries and food regulatory systems worldwide
• Food supplement approved: Permitted in food supplements and dietary supplements (Directive 2002/46/EC)
• Infant food approved: Listed as permitted mineral salt for infant formula and young children’s food (Regulation EC 609/2013)

Safety profile:

• ADI: No ADI set; “quantum satis” principle applies (use as much as needed for intended purpose)
• Toxicity studies: Extensive animal and human studies show no toxicity at any tested doses
• No carcinogenicity: No evidence of cancer-causing potential
• No reproductive effects: Safe for use during pregnancy and breastfeeding
• Natural metabolism: Body processes it identically to calcium and gluconic acid from natural sources
• Bioavailability: Provides well-absorbed, bioavailable form of calcium—more bioavailable than some other calcium salts
• Decades of safe use: In medical use since the 1920s with excellent safety record
• No documented adverse effects: No documented widespread adverse effects at food use levels

Medical uses: Calcium gluconate is so safe it’s used medically for treating low blood calcium, high potassium, and magnesium toxicity—demonstrating confidence in its safety profile.

Special populations:

• Infants and young children: Permitted in infant formula and young children’s food—indicating safety for the most vulnerable population
• Pregnant women: Safe to use; sometimes recommended for calcium supplementation
• Kidney disease patients: Generally safe; should be monitored (like all calcium intake) but not contraindicated
• People on medications: May interact with certain medications that affect calcium absorption; consult healthcare provider if concerned

Natural vs Synthetic Version

E578 is derived from natural sources (glucose) but involves processing:

Source and production:

• Gluconic acid starting material: Derived from glucose (naturally occurring sugar)
• Production methods: Fermentation (most natural) or chemical oxidation (more processed)
• Calcium bonding: Chemical process to create the salt
• Final product: Chemically identical regardless of production method

Perceived “naturalness”: E578 is often perceived as “natural” because it’s derived from glucose and calcium—both natural substances. However, regulatory classification is “food additive” rather than “natural” due to the processing involved.

Vegetarian/vegan status: E578 is vegetarian and vegan (not derived from animal products). The calcium source is inorganic mineral calcium, and the gluconic acid is produced from glucose.

Natural Alternatives

Want to avoid E578 or looking for alternatives?

Some alternatives include:

• Calcium lactate (E327) – Similar function; slightly different mineral salt form
• Calcium carbonate – Basic calcium compound; less soluble than E578
• Calcium citrate – Well-absorbed calcium form; expensive
• Calcium phosphate – Various forms available; different functional properties
• Whole food sources: Dairy products, leafy greens, fortified plant-based milks, sardines, seeds
• Bone broth – Contains naturally occurring calcium and other minerals
• Eggshell powder – Home preparation from natural source
• Sea vegetables – Seaweed contains naturally occurring calcium
• Simply avoid fortification – Use naturally calcium-rich foods instead

Comparison to Related Compounds

E578 differs from other calcium-based additives:

• E327 (Calcium lactate): Similar function; different mineral acid bonding; E578 has better solubility
• Calcium carbonate: Basic form of calcium; less soluble; less expensive; simpler chemistry
• Calcium chloride: Highly soluble; bitter taste; different functional properties
• Tricalcium phosphate: Different mineral form; less soluble; common in supplements

The Bottom Line

E578 (calcium gluconate) is one of the safest and most beneficial food additives available.

It’s found in beverages, dairy products, canned vegetables, baked goods, and fortified foods—where it serves as a stabilizer, firming agent, and calcium source.

E578 is approved by the FDA, EFSA, WHO, and virtually all regulatory bodies worldwide. It’s even safe for infants, pregnant women, and people with most medical conditions.

Key advantage over most additives: E578 isn’t just functional—it provides genuine nutritional benefit by supplying bioavailable calcium. This makes it one of the rare instances where an E-number additive actually improves the nutritional value of food rather than just improving appearance or texture.

E578 has been in medical use since the 1920s and remains on the WHO List of Essential Medicines—a trust indicator few food additives can claim.

For health-conscious consumers, E578 is actually a positive food additive to look for, as it indicates food fortified with a well-absorbed calcium source. If you’re seeking to increase calcium intake through fortified foods, E578 is one of the best mineral sources available in food additives.