Calcium inosinate is the flavor enhancer the food industry lists as E633. In our table it is no risk identified: it takes no points off a product's score.
- The key finding, from the FDA: Inosinate salts hold an affirmative US authorisation as flavouring adjuvants; no separate hazard classification exists for the calcium form (21 CFR 172.535 (disodium inosinate, govinfo CFR-2024-title21-vol3))
- No child flag. The class, and the points it costs, are the same for a child of any age.
- Where you meet it. None of the 10,000 packaged foods scanned most on Open Food Facts list it. Nine in ten of those foods are sold in Europe (counted 26 Sep 2026).
- 2 citations from the FDA and EFSA, each one below.
What Calcium inosinate does to a score
A packaged food's additive subscore starts at 100 and loses points for each additive on the label; that subscore is a third of the final score. Calcium inosinate takes no points off a product's score. Scan the pack in Sito and the score you get is the one for your own child's age, with this additive named in the reasons. How we score has the whole method.
See what is in your own cupboard
Scan a packaged food and Sito names the additives in it, then scores the product out of 100 for your child's age.
What the sources found
Every classification in our table comes from the citations below, and nothing else. Each finding is our one-line summary of what the source concluded, with the source and reference beside it.
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FDA
21 CFR 172.535 (disodium inosinate, govinfo CFR-2024-title21-vol3)
Inosinate salts hold an affirmative US authorisation as flavouring adjuvants; no separate hazard classification exists for the calcium form. -
EFSA
Call for data for the re-evaluation of ribonucleotides (E 626-635), 2023-06-28
E 633 sits inside the open ribonucleotide re-evaluation; no EFSA opinion, ADI or age-group exposure assessment has been published.
Why this class
Clean current EFSA and FDA status. These rows exist so that an unfamiliar additive is never treated as a bad one: a missing row costs a product nothing, and a clean row says so with citations.
Our confidence in this row's classification is medium. Medium or low does not mean the evidence is weak; it means something about the row is still being pinned down, usually a regulatory status confirmed from one source rather than two.
Questions parents ask
Is Calcium inosinate (E633) safe for kids?
No risk identified. No regulator finding we score, so a product keeps its full additive subscore in Sito. The current status is clean: Inosinate salts hold an affirmative US authorisation as flavouring adjuvants; no separate hazard classification exists for the calcium form (FDA, 21 CFR 172.535 (disodium inosinate, govinfo CFR-2024-title21-vol3)).
What is E633?
E633 is the E number for Calcium inosinate, a flavor enhancer. Open Food Facts tags it en:e633.
Next to it on the label
The E numbers either side of E633 in our table, then the closest flavor enhancers by number.
- Calcium guanylate (E629), no risk identified
- Inosinic acid (E630), no risk identified
- Disodium inosinate (E631), no risk identified
- Dipotassium inosinate (E632), no risk identified
- Calcium 5'-ribonucleotides (E634), no risk identified
- Disodium 5'-ribonucleotides (E635), no risk identified