E633 Calcium inosinate

E633Flavor enhancersOrigin: Plant or animal

Get a personal answer

Pick your family’s diets in the bar above.

Every diet

VeganDepends

Some versions are made by fermentation and some from animal tissue. Check the source.

Gluten-freeYes

HalalDepends

Halal status depends on the source.

KosherDepends

Kosher status depends on the source.

KetoYes

Low-FODMAPYes

The short answer

Calcium inosinate (E633) is a savory flavor booster related to disodium inosinate, used alongside MSG in snacks and stock products. It is gluten-free, but vegan, halal and kosher status depends on whether it was made by fermentation or from animal tissue.

85/100

Generally safe

Fine for most people at normal amounts.

E-numberE633

Comes fromPlant or animal

What it doesFlavor enhancers

Glycemic index—

Daily limitNot set

Also calledE633, Calcium 5'-inosinate

Rules by country

🇺🇸 US FDAApproved

🇪🇺 European UnionApproved

🇨🇦 Health CanadaApproved

CaliforniaNo extra rules

Permitted in the US, EU and Canada as a flavor enhancer in small amounts, usually together with glutamates.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

Calcium inosinate is a salt of inosinic acid, a nucleotide that adds savory depth. It is used in very small amounts and often pairs with glutamates for a stronger savory effect.

Where it comes from: Made by producing inosinic acid, usually by fermentation, and then combining it with calcium. Some older production started from animal tissue, so the source matters for strict diets.

Why it’s in food

Boosts savory flavor
Works with glutamates for extra umami
Used in small amounts

Often found in

Snack seasoningsInstant soupsStock cubes

Also listed as: E633, Calcium 5'-inosinate, Calcium IMP

Health & gut impact

GoutUnder study

Inosinic acid is broken down to uric acid. Purine-containing foods matter for people with gout, though the amounts from flavor boosters are small.

EFSA 2017 opinion on 5'-ribonucleotides

What can I use instead?

Disodium inosinate (E631)

Ratio: The same amount; it is the sodium salt

Best for: Snacks and soups

Yeast extract

Ratio: A similar amount for savory depth

Best for: Vegetarian soups

More flavor enhancers:

Artificial flavors (Artificial flavoring)Artificial flavor means the aroma was synthesized, not extracted from the food it tastes like. The category is allowed. Vegan, halal and kosher status still depends on the carrier.Use in moderation Brewer's yeastBrewer's yeast is yeast left over from making beer. It is bitter, it may contain barley gluten, and it is not the cheesy flake called nutritional yeast.Use in moderation Diacetyl (Butanedione)Diacetyl is the buttery flavor molecule. The FDA lists it as a GRAS flavor. Breathing the vapor at work has harmed lungs. Eating the trace in a food is the exposure the GRAS rule is about.Use in moderation Disodium Guanylate E627Disodium guanylate (E627) is a savory booster used with MSG. It's usually made from yeast, but can come from fish, so check for a vegan label.Generally safe

Common questions

Is calcium inosinate the same as disodium inosinate?

Both give savory flavor. Calcium inosinate adds calcium, and it is less common than the sodium version.

Does it contain MSG?

No. It is a different compound, though it is often used alongside MSG for a stronger savory effect.

Is Calcium inosinate safe?

Generally safe (85/100). Permitted in the US, EU and Canada as a flavor enhancer in small amounts, usually together with glutamates.

Is Calcium inosinate vegan?

Depends. Some versions are made by fermentation and some from animal tissue. Check the source.

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Scientific sources & regulatory citations

EFSA OpenFoodTox: E633
EFSA 2017 opinion on 5'-ribonucleotides

INS 633 · CAS 5743-27-1