A systematic review of 91 investigations of sodium bicarbonate supplementation, sorted by protocol type, found that GI symptoms rise in a dose dependent way as single doses climb from 0.2 to 0.5 g/kg body mass, and that even the standard 0.3 g/kg dose produces mild to severe symptoms in some people.
Four mitigation strategies showed promise: spreading the dose over several hours, enteric coated capsules, hydrogel delivery, and taking the dose alongside a carbohydrate containing meal or snack. The authors are candid that no study has compared these strategies head to head, and that inconsistent GI symptom measurement across the literature prevents firm recommendations.
The numbers
| Studies included, as reported in the authors' earlier poster | 91 across six protocol categories |
| Dose range | 0.2 to 0.5 g/kg body mass, most commonly 0.3 g/kg |
| Mitigation strategies showing promise | 4 (spread dosing, enteric coating, hydrogel delivery, carbohydrate co ingestion) |
What this does not show
- That any mitigation strategy beats another. The authors state directly that head to head comparisons of the four strategies are nonexistent.
- That eating carbohydrate with the dose reliably helps. The carbohydrate co ingestion result rests on a single study. It is the most interesting finding and also the thinnest.
- Effect sizes for anything. This is a systematic review without meta analysis, so it cannot quantify how much any dose or strategy changes symptoms.
- That the published paper matches the numbers quoted here. The study counts, category breakdown and dose figures were sourced from the authors' earlier November 2025 conference poster because the published abstract could not be opened during the digest run. The peer reviewed version may differ.
Caveats worth holding
- Provenance flag: the study counts, category breakdown and dose figures come from the authors' earlier conference poster (Old Dominion University, November 2025). PubMed was CAPTCHA walled during the digest run and the published August 2026 abstract could not be opened, so all specific numbers are attributed as reported and should be verified against the full text before citing.
- No head to head comparisons of mitigation strategies exist, so no ranking among them can be claimed.
- GI symptom measurement is highly inconsistent across the included studies: different instruments, assessment timing, rating scales and statistics. The authors say this is what prevents firm recommendations.
- The carbohydrate co ingestion result rests on a single study.
- Total participants across the 91 studies is not reported in the accessible material.
- A systematic review without meta analysis cannot give effect sizes.