Effects of Enteric-Coated Formulation of Sodium Bicarbonate on Bicarbonate Absorption and Gastrointestinal Discomfort
Open accessAbstract
Sodium bicarbonate is used as an ergogenic supplement to enhance people’s performances in various exercises. This study aimed to evaluate the effects of intestinal delivery of sodium bicarbonate on bicarbonate absorption and associated side effects in an experimental human trial. After preparing and assessing enteric-coated and uncoated sodium bicarbonate tablet formulations, pharmacokinetic analysis and gastrointestinal symptom tests were performed after oral administration in the human body. The dose required to increase blood bicarbonate concentration over 5 mmol∙L−1 for the purpose of improving performance during high-intensity exercise was also determined. Enteric-coated tablet formulation protects sodium bicarbonate under acidic conditions and releases bicarbonate in the intestine. Enteric-coated tablet formulation also reduced the oral dose required to achieve a blood bicarbonate concentration over 5 mmol∙L−1 from 300 mg∙kg−1 of uncoated tablet formulation to 225 mg∙kg−1. Gastrointestinal discomfort was significantly decreased for the group given 225 mg∙kg−1 enteric-coated tablets compared to that given 300 mg∙kg−1 uncoated tablets. These results suggest that enteric-coated tablet formulation could reduce the oral dose required in order to achieve a blood bicarbonate concentration over 5 mmol∙L−1 by 25%, from 300 mg∙kg−1 to 225 mg∙kg−1, along with its ability to reduce gastrointestinal discomfort associated with the dosage.
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Written from the paper’s full text.
TL;DR
Enteric-coated sodium bicarbonate tablets protected bicarbonate from acidic conditions and released it in the intestine, and in a human trial 225 mg·kg−1 enteric-coated tablets produced bicarbonate absorption/duration comparable to 300 mg·kg−1 uncoated tablets. The enteric-coated dose also reduced several gastrointestinal symptoms, suggesting a possible 25% dose reduction from the usual 300 mg·kg−1.
Key findings
- Enteric-coated tablets resisted disintegration at pH 1.2 for 2 h, while uncoated tablets disintegrated within 8 min at pH 7.4 and enteric-coated tablets within 25 min at pH 7.4.
- For 225 mg·kg−1 enteric-coated tablets, Tmax increased 1.85-fold vs. 225 mg·kg−1 uncoated tablets (p < 0.01, g = 2.14) and 1.49-fold vs. 300 mg·kg−1 uncoated tablets (p < 0.05, g = 1.16); Cmax and ΔCmax were not significantly different from either uncoated group.
- ΔAUC over Δ5 mmol·L−1 and duration time over Δ5 mmol·L−1 were 2.66-fold and 2.48-fold higher, respectively, for 225 mg·kg−1 enteric-coated tablets than for 225 mg·kg−1 uncoated tablets (p < 0.05), and were not statistically different from 300 mg·kg−1 uncoated tablets.
- Compared with 300 mg·kg−1 uncoated tablets, 225 mg·kg−1 enteric-coated tablets significantly lowered stomach bloating (1.33 ± 0.88 vs. 8.14 ± 2.63, p < 0.05), stomachache (0.67 ± 0.33 vs. 4.43 ± 1.32, p < 0.01), and flatulence (2.00 ± 0.93 vs. 9.14 ± 2.15, p < 0.05), but belching increased vs. 225 mg·kg−1 uncoated tablets (4.89 ± 1.34 vs. 1.14 ± 0.99, p < 0.05).
Methods
- Uncoated and enteric-coated sodium bicarbonate tablets were prepared and evaluated for weight, hardness, diameter, thickness, friability, and disintegration at pH 1.2 and pH 7.4.
- Experimental human trial: 18 healthy males (mean age 23.3 ± 1.7 years, height 1.75 ± 0.01 m, body weight 74.0 ± 3.2 kg) were initially recruited; final groups included 10 participants for 225 mg·kg−1 enteric-coated tablets and 7 each for 225 and 300 mg·kg−1 uncoated tablets, with 44% compliance and independent rather than paired analysis.
- Participants received uncoated 300 mg·kg−1, uncoated 225 mg·kg−1, or enteric-coated 225 mg·kg−1 sodium bicarbonate; blood was sampled every 30 min from 0 to 360 min, and gastrointestinal symptoms were self-rated on a 10-point scale. Pharmacokinetic parameters used non-compartmental analysis, and statistics used Kruskal–Wallis with Mann–Whitney post hoc tests, Bonferroni correction, one-tailed p < 0.05, and Hedge’s g effect sizes.
Limitations
- The paper states this was a limited case study involving seven to ten participants, so verification power was low; it calls for a randomized controlled trial with sufficient case numbers.
- The intended crossover design was not fully conducted: 10 of 18 participants dropped out, compliance was 44%, and statistical analysis used independent comparison rather than paired dependent comparison.
- Evident from the text: the trial enrolled only healthy males and did not test exercise performance, since exercising was not allowed during the trial because it could affect bicarbonate absorption.
Model-written summary. Check it against the paper before relying on it.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
11 of 22 cited sources checked · 9 supported · 0 flagged · accuracy not yet measured
- Premisecitation
The common or recommended dose of oral sodium bicarbonate supplement is 300 mg/kg body mass.
“The common or recommended dose of oral sodium bicarbonate supplement is 300 mg·kg−1 body mass [23,24,25,26,27,28]”
Quote in the paperNot a substantial claim1 of 6 sources checked- cites [23] Calvo, 2021, Effect of sodium bicarbonate contribution on energy metabolism during exercise: A systematic review and meta-analysis, J. Int. Soc. Sports Nutr. source
- cites [24] Siegler, 2012, Sodium Bicarbonate Supplementation and Ingestion Timing: Does it matter?, J. Strength Cond. Res. source
- cites [25] Carr, 2011, Effect of Sodium Bicarbonate on [HCO3−], pH, and Gastrointestinal Symptoms, Int. J. Sport Nutr. Exerc. Metab. source
- cites [26] Carr, 2011, Effects of Acute Alkalosis and Acidosis on Performance: A meta-analysis, Sports Med. source
- cites [27] Burke, 2007, Bicarbonate Loading to Enhance Training and Competitive Performance, Int. J. Sports Physiol. Perform. source
- cites [28] McNaughton, 1992, Bicarbonate ingestion: Effects of dosage on 60 s cycle ergometry, J. Sports Sci. source
- Premisecitation
Blood bicarbonate levels increased by approximately 5-6 mmol/L are considered sufficient to maintain or improve the buffering and contraction capacity of muscles.
“Such levels are considered sufficient to maintain or improve the buffering and contraction capacity of muscles [29,31].”
Quote in the paperSubstantial claim2 of 2 sources checked- cites [29] Heibel, 2018, Time to Optimize Supplementation: Modifying Factors Influencing the Individual Responses to Extracellular Buffering Agents, Front. Nutr. source
The ‘Increases in circulating bicarbonate’ section says a rise of approximately 5–6 mmol/L should be sufficient to improve exercise capacity and performance through increased extracellular buffering. The ‘Role of pH in skeletal muscle fatigue’ section explains how acidosis can hinder muscle contraction, but the paper does not establish that this bicarbonate rise maintains or improves muscles’ own buffering and contraction capacities. (LLM, conf=0.82)
Experimental — accuracy not yet measured - cites [31] Jones, 2016, Dose-Response of Sodium Bicarbonate Ingestion Highlights Individuality in Time Course of Blood Analyte Responses, Int. J. Sport Nutr. Exerc. Metab. source
- Premisecitation
300 mg/kg oral sodium bicarbonate can increase blood bicarbonate concentration by approximately 5-6 mmol/L.
“which can increase the concentration of blood bicarbonate ions by approximately 5–6 mmol·L−1 [29,30,31].”
Quote in the paperSubstantial claim3 of 3 sources checked- cites [29] Heibel, 2018, Time to Optimize Supplementation: Modifying Factors Influencing the Individual Responses to Extracellular Buffering Agents, Front. Nutr. source
- cites [30] Saunders, 2014, Sodium Bicarbonate and High-Intensity-Cycling Capacity: Variability in Responses, Int. J. Sports Physiol. Perform. source
- cites [31] Jones, 2016, Dose-Response of Sodium Bicarbonate Ingestion Highlights Individuality in Time Course of Blood Analyte Responses, Int. J. Sport Nutr. Exerc. Metab. source
- Premisecitation
Bicarbonate ions are absorbed by an active ion transport process involving hydrogen ion secretion in the small intestine.
“They are also absorbed by an active ion transport process involving hydrogen ion secretion in the small intestine [39,40].”
Quote in the paperSubstantial claim2 of 2 sources checked- cites [39] Grgic, 2021, International Society of Sports Nutrition position stand: Sodium bicarbonate and exercise performance, J. Int. Soc. Sports Nutr. source
- cites [40] Turnberg, 1970, Mechanism of bicarbonate absorption and its relationship to sodium transport in the human jejunum, J. Clin. Investig. source
- Premisecitation
Bicarbonate ions are transported into the blood through the stomach.
“Bicarbonate ions are known to be transported into the blood through the stomach [38,39].”
Quote in the paperSubstantial claim1 of 2 sources checked- cites [38] Petrovic, 2003, Identification of a basolateral Cl−/HCO 3 − exchanger specific to gastric parietal cells, Am. J. Physiol.-Gastrointest. Liver Physiol. source
- cites [39] Grgic, 2021, International Society of Sports Nutrition position stand: Sodium bicarbonate and exercise performance, J. Int. Soc. Sports Nutr. source
- Findingown data
Enteric-coated tablet formulation protects sodium bicarbonate under acidic conditions.
“Enteric-coated tablets (n = 6) passed the disintegration test in pH 1.2 solution for 2 h, indicating that the enteric coating protected sodium bicarbonate under acidic conditions.”
- Also stated in: § Abstract · plain
“Enteric-coated tablet formulation protects sodium bicarbonate under acidic conditions and releases bicarbonate in the intestine.”
Quote in the paperSubstantial claim - Also stated in: § Abstract · plain
- Findingown data
Gastrointestinal discomfort was significantly decreased for the group given 225 mg/kg enteric-coated tablets compared to the group given 300 mg/kg uncoated tablets.
“Gastrointestinal discomfort was significantly decreased for the group given 225 mg∙kg−1 enteric-coated tablets compared to that given 300 mg∙kg−1 uncoated tablets.”
- Also stated in: § 5. Conclusions · plain
“It can also decrease gastrointestinal discomfort associated with the high oral dose.”
Quote in the paperSubstantial claim - Also stated in: § 5. Conclusions · plain
- Findingown data
At 90 min, the total symptom scores of participants given 225 mg/kg enteric-coated tablets were significantly decreased by 0.27-fold compared to those given 300 mg/kg uncoated tablets.
“However, at 60 min and 90 min, the total symptom scores of participants given 225 mg∙kg−1 of enteric-coated tablets were significantly decreased by 0.12-fold and 0.27-fold, respectively, compared to those given 300 mg∙kg−1 of uncoated tablets (2.00 ± 2.96 vs. 16.29 ± 11.40, p < 0.01 at 60 min, 4.00 ± 3.35 vs. 14.71 ± 11.22, p < 0.05 at 90 min) (Figure 3).”
Quote in the paperSubstantial claim - Findingown data
The group given 225 mg/kg enteric-coated tablets did not show statistically significant differences in Cmax or ΔCmax compared to both groups given uncoated tablets at doses of 225 mg/kg and 300 mg/kg.
“although the group given 225 mg∙kg−1 enteric-coated tablets did not show statistically significant differences in Cmax or ΔCmax compared to both groups given uncoated tablets at doses of 225 mg∙kg−1 (Cmax: p = 0.81, g = 0.20; ΔCmax: p = 0.13, g = 0.74) and 300 mg∙kg−1 (Cmax: p = 0.06, g = 1.10; ΔCmax: p = 0.47, g = 0.29).”
Quote in the paperSubstantial claim - Findingown data
The total symptom severity at each time point was not different between the group given enteric-coated tablets and the group given uncoated tablets at the same dose of 225 mg/kg.
“The total symptom severity at each time point was not different between the group given enteric-coated tablets and the group given uncoated tablets at the same dose of 225 mg∙kg−1.”
Quote in the paperSubstantial claim - Findingown data
The average of individual summed scores with 225 mg/kg enteric-coated tablets did not significantly differ from those with 225 mg/kg uncoated tablets for any symptom except for belching.
“In addition, the average of the individual summed scores with 225 mg∙kg−1 enteric-coated tablets did not significantly differ from those with 225 mg∙kg−1 uncoated tablets for any symptom except for belching”
Quote in the paperSubstantial claim - Findingown data
The average of individual summed scores at all time points after administration of 225 mg/kg enteric-coated tablets did not significantly differ from that after administration of 300 mg/kg uncoated tablets for symptoms of belching, bowel urgency, stomach cramps, diarrhea, nausea, vomiting, or others.
“The average of individual summed scores at all time points after administration of 225 mg∙kg−1 enteric-coated tablets did not significantly differ from that after administration of 300 mg∙kg−1 of uncoated tablets for symptoms of belching, bowel urgency, stomach cramps, diarrhea, nausea, vomiting, or others”
Quote in the paperSubstantial claim - Findingown data
The duration time over Δ5 mmol/L in the group given 225 mg/kg enteric-coated tablets was significantly increased by 2.48-fold compared to the group given 225 mg/kg uncoated tablets.
“In particular, the ΔAUC over Δ5 mmol∙L−1 and duration time over Δ5 mmol∙L−1 in the groups given 225 mg∙kg−1 enteric-coated tablets were significantly increased by 2.66-fold (p < 0.05, g = 0.72) and 2.48-fold (p < 0.05, g = 1.15) compared to the group given uncoated tablets at a dose of 225 mg∙kg−1”
Quote in the paperSubstantial claim - Findingown data
The Tmax for the group given 225 mg/kg enteric-coated tablets was increased by 1.85-fold compared to the group given 225 mg/kg uncoated tablets.
“The Tmax for the group given 225 mg∙kg−1 enteric-coated tablets was increased by 1.85-fold (p < 0.01, g = 2.14) and 1.49-fold (p < 0.05, g = 1.16), respectively, compared to the groups given 225 mg∙kg−1 and 300 mg∙kg−1 uncoated tablets”
Quote in the paperSubstantial claim - Findingown data
At 60 min, the total symptom scores of participants given 225 mg/kg enteric-coated tablets were significantly decreased by 0.12-fold compared to those given 300 mg/kg uncoated tablets.
“However, at 60 min and 90 min, the total symptom scores of participants given 225 mg∙kg−1 of enteric-coated tablets were significantly decreased by 0.12-fold and 0.27-fold, respectively, compared to those given 300 mg∙kg−1 of uncoated tablets (2.00 ± 2.96 vs. 16.29 ± 11.40, p < 0.01 at 60 min, 4.00 ± 3.35 vs. 14.71 ± 11.22, p < 0.05 at 90 min) (Figure 3).”
Quote in the paperSubstantial claim - Findingown data
The increase in blood bicarbonate concentration changes was slower in the group given 225 mg/kg enteric-coated tablets than in the group given uncoated tablets regardless of dose.
“Figure 1 shows that the increase in the blood bicarbonate concentration changes was slower in the group given 225 mg∙kg−1 enteric-coated tablets than in the group given the uncoated tablets regardless of the dose”
Quote in the paperSubstantial claim - Findingown data
The enteric-coated tablets fully dissolved at pH 7.4 in the disintegration test.
“Also, the enteric-coated tablets resisted without porosity or cracking for 2 h at pH 1.2, and were fully dissolved at pH 7.4 in the disintegration test, indicating that the release of bicarbonate from the enteric-coated formulation occurred in the intestine.”
Quote in the paperSubstantial claim - Findingown data
The enteric-coated tablets passed the disintegration test in pH 1.2 solution for 2 h.
“Enteric-coated tablets (n = 6) passed the disintegration test in pH 1.2 solution for 2 h, indicating that the enteric coating protected sodium bicarbonate under acidic conditions.”
Quote in the paperSubstantial claim - Findingown data
The Tmax for the group given 225 mg/kg enteric-coated tablets was increased by 1.49-fold compared to the group given 300 mg/kg uncoated tablets.
“The Tmax for the group given 225 mg∙kg−1 enteric-coated tablets was increased by 1.85-fold (p < 0.01, g = 2.14) and 1.49-fold (p < 0.05, g = 1.16), respectively, compared to the groups given 225 mg∙kg−1 and 300 mg∙kg−1 uncoated tablets”
Quote in the paperSubstantial claim - Findingown data
The ΔCmax in the group given 225 mg/kg enteric-coated tablets was not lower than in the group given 300 mg/kg uncoated tablets.
“and the ΔCmax in the group given 225 mg∙kg−1 enteric-coated tablets, unlike in the group given 225 mg∙kg−1 uncoated tablets, was not lower than in the group given 300 mg∙kg−1 uncoated tablets.”
Quote in the paperSubstantial claim - Findingown data
The differences between the maximum and minimum values of pH, electrolytes (Na+, K+, Cl−), lactate, and pCO2 in blood for the group given 225 mg/kg enteric-coated tablets were not significantly different from those in the group given uncoated tablets at a dose of 225 or 300 mg/kg.
“In addition, the differences between the maximum and minimum values of pH, electrolytes (Na+, K+, Cl−), lactate, and pCO2 in blood for the group given 225 mg∙kg−1 enteric-coated tablets were not significantly different from those in the group given uncoated tablets at a dose of 225 or 300 mg∙kg−1, indicating that the enteric coating neither significantly reduced nor increased endogenous parameters”
Quote in the paperSubstantial claim - Findingown data
The ΔAUC over Δ5 mmol/L in the group given 225 mg/kg enteric-coated tablets was significantly increased by 2.66-fold compared to the group given 225 mg/kg uncoated tablets.
“In particular, the ΔAUC over Δ5 mmol∙L−1 and duration time over Δ5 mmol∙L−1 in the groups given 225 mg∙kg−1 enteric-coated tablets were significantly increased by 2.66-fold (p < 0.05, g = 0.72) and 2.48-fold (p < 0.05, g = 1.15) compared to the group given uncoated tablets at a dose of 225 mg∙kg−1”
Quote in the paperSubstantial claim - Findingown data
Belching scores of participants given enteric-coated tablets increased by 4.28-fold compared to those of participants given uncoated tablets at a dose of 225 mg/kg.
“On the contrary, the belching scores of participants given enteric-coated tablets increased by 4.28-fold compared to those of participants given uncoated tablets at a dose of 225 mg∙kg−1 (4.89 ± 1.34 vs. 1.14 ± 0.99, p < 0.05, g = 1.06).”
Quote in the paperSubstantial claim - Interpretationown data
Enteric-coated tablet formulation reduces the oral dose required to achieve a blood bicarbonate concentration over 5 mmol/L from 300 mg/kg uncoated to 225 mg/kg.
“Enteric-coated tablet formulation also reduced the oral dose required to achieve a blood bicarbonate concentration over 5 mmol∙L−1 from 300 mg∙kg−1 of uncoated tablet formulation to 225 mg∙kg−1.”
- Also stated in: § 5. Conclusions · hedged
“The present study suggests that the enteric-coated tablet formulation can reduce the oral dose of sodium bicarbonate by 25% from the most common oral dose of 300 mg·kg−1, which is required in order to achieve a sufficient blood bicarbonate concentration change to 225 mg·kg−1.”
Quote in the paperSubstantial claim - Also stated in: § 5. Conclusions · hedged
- Interpretationown data
Enteric-coated tablet formulation releases bicarbonate in the intestine.
“Enteric-coated tablet formulation protects sodium bicarbonate under acidic conditions and releases bicarbonate in the intestine.”
- Also stated in: § 4. Discussion · hedged
“Also, the enteric-coated tablets resisted without porosity or cracking for 2 h at pH 1.2, and were fully dissolved at pH 7.4 in the disintegration test, indicating that the release of bicarbonate from the enteric-coated formulation occurred in the intestine.”
Quote in the paperSubstantial claim - Also stated in: § 4. Discussion · hedged
- Study design and conductown data
The compliance rate was 44%.
“Therefore, the compliance rate was 44% [(10 + 7 + 7)/(18 × 3) = (24/54) = 0.44].”
Quote in the paperSubstantial claim - Interpretationown data
The extent of bicarbonate absorption over 5 mmol/L and the duration time at the lower dose were recovered by an enteric-coated formulation that extended the absorption time and protected sodium bicarbonate under acidic conditions.
“These results demonstrate that the extent of bicarbonate absorption over 5 mmol∙L−1 and the duration time at the lower dose were recovered by an enteric-coated formulation that extended the absorption time and protected sodium bicarbonate under acidic conditions.”
Quote in the paperSubstantial claim - Premisecitation
Administration of sodium bicarbonate supplements is associated with gastrointestinal symptoms in approximately 30% of athletes.
“However, administration of sodium bicarbonate supplements is associated with adverse effects, i.e., gastrointestinal symptoms, in ~30% of athletes [25,26,27].”
Quote in the paperSubstantial claim0 of 3 sources checked- cites [25] Carr, 2011, Effect of Sodium Bicarbonate on [HCO3−], pH, and Gastrointestinal Symptoms, Int. J. Sport Nutr. Exerc. Metab. source
- cites [26] Carr, 2011, Effects of Acute Alkalosis and Acidosis on Performance: A meta-analysis, Sports Med. source
- cites [27] Burke, 2007, Bicarbonate Loading to Enhance Training and Competitive Performance, Int. J. Sports Physiol. Perform. source
- Interpretationown data
The enteric-coated formulations of 225 mg/kg tablets had an absorption capacity similar to that of 300 mg/kg uncoated tablets.
“Consequently, the enteric-coated formulations of 225 mg∙kg−1 tablets had an absorption capacity similar to that of 300 mg∙kg−1 uncoated tablets”
Quote in the paperSubstantial claim - Premisecitation
Some gastrointestinal side effects of sodium bicarbonate might be caused by carbon dioxide gas produced through carbonic acid after neutralization of sodium bicarbonate by gastric acid in the stomach.
“Some of these side effects might be caused by carbon dioxide gas, which is produced through carbonic acid after neutralization of sodium bicarbonate by gastric acid in the stomach [34].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [34] Fordtran, 1984, Gas Production After Reaction of Sodium Bicarbonate and Hydrochloric Acid, Gastroenterology source
- Classified as probably not a substantial claim. 5
- May combine two claims. 7
Classified as probably not a substantial claim. May combine two claims.
PremisecitationA recent study of enteric-coated sodium bicarbonate capsules reported that blood bicarbonate concentrations and group gastrointestinal symptom scores are not significantly different between groups administered enteric-coated capsules and uncoated gelatin capsules.
“However, a recent study of enteric-coated sodium bicarbonate capsules has reported that blood bicarbonate concentrations and group gastrointestinal symptom scores are not significantly different between groups administered enteric-coated capsules and uncoated gelatin capsules [5].”
Quote in the paperSubstantial claim1 of 1 sources checked- cites [5] Hilton, 2020, Enteric-coated sodium bicarbonate supplementation improves high-intensity cycling performance in trained cyclists, Eur. J. Appl. Physiol. source
Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
Experimental — accuracy not yet measured
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationAnother paper reported that blood bicarbonate concentrations were lower in the group administered enteric-coated capsules than in the group administered uncoated gelatin capsules.
“On the other hand, another paper has reported that blood bicarbonate concentrations were lower in the group administered enteric-coated capsules than in the group administered uncoated gelatin capsules [36].”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [36] Hilton, 2020, Enteric-Coated Sodium Bicarbonate Attenuates Gastrointestinal Side-Effects, Int. J. Sport Nutr. Exerc. Metab. source
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Findingnone givenThe enteric-coated tablet surface was free from pores or cracks, indicating a consistent coating process.
“The enteric-coated tablet surface was free from pores or cracks, indicating a consistent coating process.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Findingown dataBoth uncoated and enteric-coated tablets had good physical integrity.
“These values indicate that both tablets had good physical integrity.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe disintegration time in pH 7.4 buffer was within 8 min for uncoated tablets and within 25 min for enteric-coated tablets.
“The disintegration time in pH 7.4 buffer was within 8 min for uncoated tablets (n = 6) and within 25 min for enteric-coated tablets (n = 6).”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe ΔAUC over Δ5 mmol/L and duration time over Δ5 mmol/L in the group given 225 mg/kg enteric-coated tablets were not statistically different from those given 300 mg/kg uncoated tablets.
“and were not statistically different from those given 300 mg∙kg−1 uncoated tablets (ΔAUC over Δ5 mmol∙L−1: p = 0.96, g = 0.04; duration time over Δ5 mmol∙L−1: p = 0.89, g = 0.06) (Table 1).”
Quote in the paperSubstantial claimMay combine two claims.
PremisecitationEnteric coating protects orally administered formulations from damage by acidic pH and increases absorption in the intestine.
“Enteric coating is the usual procedure used to protect orally administered formulations from damage by acidic pH to avoid undesirable effects on the stomach, and is used to increase absorption in the intestine [37].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [37] Maderuelo, 2019, Enteric coating of oral solid dosage forms as a tool to improve drug bioavailability, Eur. J. Pharm. Sci. source
May combine two claims.
Study design and conductown dataThis study conducted a limited case study involving seven to ten participants, resulting in low verification power.
“This study conducted a limited case study involving seven to ten participants to examine the effects of sodium bicarbonate. As a result, there was a limitation in that the verification power was kept low.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim. May combine two claims.
Study design and conductreasoningAs the crossover design was not fully conducted, along with poor compliance, statistical analysis was conducted through independent comparison, not through paired dependent comparison.
“As the crossover design was not fully conducted, along with poor compliance, statistical analysis was conducted through independent comparison, not through paired dependent comparison.”
Quote in the paperSubstantial claim
The authors state this as an assumption.
Sodium bicarbonate contributes to acid-base balance by buffering excess hydrogen ions.
“It is assumed to contribute to acid–base balance by buffering excess hydrogen ions [3].”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Discussion incorrectly says belching significantly decreased
MinorThe discussion includes belching among symptoms significantly decreased relative to the 300 mg∙kg−1 uncoated group, but the results report no significant difference for belching in that comparison (p = 0.47).
“The severity scores for gastrointestinal symptoms, especially stomach bloating, belching, stomachache, and flatulence, were significantly decreased for the group given 225 mg∙kg−1 enteric-coated tablets, especially between 60 and 120 min, compared to those given 300 mg∙kg−1 uncoated tablets.”
“did not significantly differ from that after administration of 300 mg∙kg−1 of uncoated tablets for symptoms of belching, bowel urgency, stomach cramps, diarrhea, nausea, vomiting, or others (belching, p = 0.47, g = 0.45;”
Cites
Lakens, D. (2013) · Frontiers in Psychology · doi:10.3389/fpsyg.2013.00863 · Cited by 10,303 · cited 1× · see citing works
“Effect sizes were calculated using Hedge’s g for paired comparisons [41], and were described as small (g = 0.2), medium (g = 0.5), or large (g = 0.8) [42].”
MethodInfluentialCellular mechanisms of muscle fatigue
Fitts, R. H. (1994) · Physiological Reviews · doi:10.1152/physrev.1994.74.1.49 · Cited by 1,537 · cited 1× · see citing works
“The accumulation of hydrogen ions can cause acidification in the muscle, which is associated with muscle fatigue and muscle contraction disturbances [6–8].”
BackgroundIOC Consensus Statement: Dietary Supplements and the High-performance Athlete
Maughan, R. J., Burke, L. M., Dvorak, J., Larson-Meyer, D. E., Peeling, P., Phillips, S. M., Rawson, E. S., Walsh, N. P., Garthe, I., Geyer, H., et al. (2018) · British Journal of Sports Medicine · doi:10.1136/bjsports-2018-099027 · Cited by 1,004 · cited 1× · see citing works
“%) in short-term, high-intensity sprints lasting ~60 s in duration for 10 min [22].”
BackgroundIOC Consensus Statement: Dietary Supplements and the High-Performance Athlete
Maughan, R. J., Burke, L. M., Dvorak, J., Larson-Meyer, D. E., Peeling, P., Phillips, S. M., Rawson, E. S., Walsh, N. P., Garthe, I., Geyer, H., et al. (2018) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.2018-0020 · Cited by 540 · see citing works
Effects of Acute Alkalosis and Acidosis on Performance: A Meta-Analysis
Carr, A. J., Hopkins, W. G., & Gore, C. J. (2011) · Sports Medicine · doi:10.2165/11591440-000000000-00000 · Cited by 277 · see citing works
Kent‐Braun, J. A., Fitts, R. H., & Christie, A. D. (2012) · Comprehensive physiology · doi:10.1002/cphy.c110029 · Cited by 232 · see citing works
Mechanism of bicarbonate absorption and its relationship to sodium transport in the human jejunum
Turnberg, L. A., Fordtran, J. S., Carter, N. W., & Rector, F. C. (1970) · Journal of Clinical Investigation · doi:10.1172/jci106265 · Cited by 225 · cited 2× · see citing works
“Given that sodium bicarbonate could become instable due to gastric acid, enteric coating might increase bicarbonate absorption while reducing its side effects [37–40].”
BackgroundEffect of sodium bicarbonate on [HCO3-], pH, and gastrointestinal symptoms
Carr, A. J., Slater, G. J., Gore, C. J., Dawson, B., & Burke, L. M. (2011) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.21.3.189 · Cited by 159 · cited 2× · see citing works
“It can also decrease gastrointestinal discomfort associated with the high oral dose.”
BackgroundEffects of induced metabolic alkalosis on prolonged intermittent-sprint performance
BISHOP, D., & CLAUDIUS, B. (2005) · Medicine & Science in Sports & Exercise · doi:10.1249/01.mss.0000161803.44656.3c · Cited by 155 · see citing works
Enteric coating of oral solid dosage forms as a tool to improve drug bioavailability
Maderuelo, C., Lanao, J. M., & Zarzuelo, A. (2019) · European Journal of Pharmaceutical Sciences · doi:10.1016/j.ejps.2019.105019 · Cited by 147 · cited 2× · see citing works
“Given that sodium bicarbonate could become instable due to gastric acid, enteric coating might increase bicarbonate absorption while reducing its side effects [37–40].”
BackgroundGrgic, J., Pedisic, Z., Saunders, B., Artioli, G. G., Schoenfeld, B. J., McKenna, M. J., Bishop, D. J., Kreider, R. B., Stout, J. R., Kalman, D. S., et al. (2021) · Journal of the International Society of Sports Nutrition · doi:10.1186/s12970-021-00458-w · Cited by 138 · cited 2× · see citing works
“Bicarbonate ions are known to be transported into the blood through the stomach [38,39].”
BackgroundKraut, J. A., & Kurtz, I. (2006) · Clinical and Experimental Nephrology · doi:10.1007/s10157-006-0408-9 · Cited by 129 · see citing works
Bicarbonate ingestion: Effects of dosage on 60 s cycle ergometry
McNaughton, L. R. (1992) · Journal of Sports Sciences · doi:10.1080/02640419208729940 · Cited by 120 · cited 1× · see citing works
“The common or recommended dose of oral sodium bicarbonate supplement is 300 mg · kg − 1 body mass [23–28], which can increase the concentration of blood bicarbonate ions by approximately 5–6 mmol · L − 1 [29–31].”
BackgroundSodium Bicarbonate Improves Swimming Performance
Lindh, A., Peyrebrune, M., Ingham, S., Bailey, D., & Folland, J. (2008) · International Journal of Sports Medicine · doi:10.1055/s-2007-989228 · Cited by 109 · see citing works
Sodium Bicarbonate and High-Intensity-Cycling Capacity: Variability in Responses
Saunders, B., Sale, C., Harris, R. C., & Sunderland, C. (2014) · International Journal of Sports Physiology and Performance · doi:10.1123/ijspp.2013-0295 · Cited by 105 · see citing works
Effects of Sodium Bicarbonate Ingestion on Prolonged Intermittent Exercise
Price, M., MOSS, P., & RANCE, S. (2003) · Medicine & Science in Sports & Exercise · doi:10.1249/01.mss.0000079067.46555.3c · Cited by 100 · see citing works
Heibel, A. B., Perim, P. H. L., Oliveira, L. F., McNaughton, L. R., & Saunders, B. (2018) · Frontiers in Nutrition · doi:10.3389/fnut.2018.00035 · Cited by 92 · cited 3× · see citing works
“The duration time of bicarbonate in the blood was defined as the time needed to maintain a bicarbonate concentration above 5 mmol · L − 1 , since performance improvement has been observed in most studies when the blood bicarbonate concentration increased by more than 5 mmol from the baseline [29].”
BackgroundIdentification of a basolateral Cl<sup>−</sup>/HCO 3 − exchanger specific to gastric parietal cells
Petrovic, S., Ju, X., Barone, S., Seidler, U., Alper, S. L., Lohi, H., Kere, J., & Soleimani, M. (2003) · American Journal of Physiology-Gastrointestinal and Liver Physiology · doi:10.1152/ajpgi.00454.2002 · Cited by 91 · see citing works
Cameron, S. L., McLay-Cooke, R. T., Brown, R. C., Gray, A. R., & Fairbairn, K. A. (2010) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.20.4.307 · Cited by 91 · cited 1× · see citing works
“The most commonly reported side effect is gastrointestinal discomfort, including stomach bloating, belching, bowel urgency, stomachache, stomach cramps, flatulence, diarrhea, nausea, and vomiting [32,33].”
BackgroundJones, R. L., Stellingwerff, T., Artioli, G. G., Saunders, B., Cooper, S., & Sale, C. (2016) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.2015-0286 · Cited by 75 · cited 2× · see citing works
“The common or recommended dose of oral sodium bicarbonate supplement is 300 mg · kg − 1 body mass [23–28], which can increase the concentration of blood bicarbonate ions by approximately 5–6 mmol · L − 1 [29–31].”
BackgroundKrustrup, P., Ermidis, G., & Mohr, M. (2015) · Journal of the International Society of Sports Nutrition · doi:10.1186/s12970-015-0087-6 · Cited by 74 · see citing works
Lopes-Silva, J., Santos, J. F. D. S., Artioli, G., Loturco, I., Abbiss, C., & Franchini, E. (2018) · European Journal of Sport Science · doi:10.1080/17461391.2018.1424942 · Cited by 70 · see citing works
Bicarbonate Loading to Enhance Training and Competitive Performance
Burke, L. M., & Pyne, D. B. (2007) · International Journal of Sports Physiology and Performance · doi:10.1123/ijspp.2.1.93 · Cited by 68 · cited 1× · see citing works
“However, administration of sodium bicarbonate supplements is associated with adverse effects, i.e., gastrointestinal symptoms, in ~30% of athletes [25–27].”
BackgroundKahle, L. E., Kelly, P. V., Eliot, K. A., & Weiss, E. P. (2013) · Nutrition Research · doi:10.1016/j.nutres.2013.04.009 · Cited by 61 · cited 1× · see citing works
“The most commonly reported side effect is gastrointestinal discomfort, including stomach bloating, belching, bowel urgency, stomachache, stomach cramps, flatulence, diarrhea, nausea, and vomiting [32,33].”
BackgroundSodium Bicarbonate Ingestion and Repeated Swim Sprint Performance
Siegler, J. C., & Gleadall-Siddall, D. O. (2010) · The Journal of Strength and Conditioning Research · doi:10.1519/jsc.0b013e3181f55eb1 · Cited by 57 · see citing works
Durkalec-Michalski, K., Zawieja, E. E., Podgórski, T., Łoniewski, I., Zawieja, B., Warzybok, M., & Jeszka, J. (2018) · PLoS ONE · doi:10.1371/journal.pone.0197480 · Cited by 55 · see citing works
Sodium Bicarbonate Supplementation and Ingestion Timing: Does It Matter?
Siegler, J. C., Marshall, P. W. M., Bray, J., & Towlson, C. (2012) · Journal of Strength and Conditioning Research · doi:10.1519/jsc.0b013e3182392960 · Cited by 54 · see citing works
Hilton, N. P., Leach, N. K., Sparks, S. A., Gough, L. A., Craig, M. M., Deb, S. K., & McNaughton, L. R. (2019) · Sports Medicine - Open · doi:10.1186/s40798-019-0177-0 · Cited by 46 · see citing works
Effects of sodium bicarbonate supplementation on exercise performance: an umbrella review
Grgić, J., Grgic, I., Coso, J. D., Schoenfeld, B. J., & Pedišić, Ž. (2021) · Journal of the International Society of Sports Nutrition · doi:10.1186/s12970-021-00469-7 · Cited by 46 · cited 1× · see citing works
“Over the past few decades, many papers have shown that sodium bicarbonate as an ergogenic supplement can enhance people’s performance in various exercises, including running, cycling, rowing, sprinting, and swimming [13–21].”
BackgroundThe Role of Intracellular Acidosis in Muscle Fatigue
Allen, D. G., Westerblad, H., & Lännergren, J. (1995) · Advances in experimental medicine and biology · doi:10.1007/978-1-4899-1016-5_5 · Cited by 43 · see citing works
Durkalec‐Michalski, K., Zawieja, E. E., Zawieja, B. E., Michałowska, P., & Podgórski, T. (2020) · Scientific Reports · doi:10.1038/s41598-020-57590-x · Cited by 41 · see citing works
Gas Production After Reaction of Sodium Bicarbonate and Hydrochloric Acid
Fordtran, J. S., Morawski, S. G., Santa Ana, C. A., & Rector, F. C. (1984) · Gastroenterology · doi:10.1016/s0016-5085(84)80059-1 · Cited by 36 · cited 1× · see citing works
“Some of these side effects might be caused by carbon dioxide gas, which is produced through carbonic acid after neutralization of sodium bicarbonate by gastric acid in the stomach [34].”
BackgroundDelextrat, A., Mackessy, S., Arceo-Rendon, L., Scanlan, A., Ramsbottom, R., & Calleja-Gonzalez, J. (2018) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.2017-0353 · Cited by 35 · see citing works
Bicarbonate Therapy for Critically Ill Patients with Metabolic Acidosis: A Systematic Review
Ghauri, S. K., Javaeed, A., Mustafa, K. J., Podlasek, A., & Khan, A. S. (2019) · Cureus · doi:10.7759/cureus.4297 · Cited by 35 · cited 1× · see citing works
“Sodium bicarbonate is used to treat metabolic acidosis with low blood pH levels due to reduced concentrations of bicarbonate ions in the plasma [1–3].”
MethodHilton, N. P., Leach, N. K., Hilton, M. M., Sparks, S. A., & McNaughton, L. R. (2020) · European Journal of Applied Physiology · doi:10.1007/s00421-020-04387-5 · Cited by 35 · cited 4× · see citing works
“However, a recent study of enteric-coated sodium bicarbonate capsules has reported that blood bicarbonate concentrations and group gastrointestinal symptom scores are not significantly different between groups administered enteric-coated capsules and uncoated gelatin capsules [5].”
BackgroundInfluentialCalvo, J. L., Xu, H., Mon-López, D., Pareja-Galeano, H., & Jiménez, S. L. (2021) · Journal of the International Society of Sports Nutrition · doi:10.1186/s12970-021-00410-y · Cited by 30 · cited 1× · see citing works
“The common or recommended dose of oral sodium bicarbonate supplement is 300 mg · kg − 1 body mass [23–28], which can increase the concentration of blood bicarbonate ions by approximately 5–6 mmol · L − 1 [29–31].”
BackgroundDurkalec-Michalski, K., Nowaczyk, P., Adrian, J., Kamińska, J., & Podgórski, T. (2020) · Nutrition and Metabolism · doi:10.1186/s12986-020-00457-9 · Cited by 25 · cited 1× · see citing works
“…in an attempt to increase the extracellular buffering capacity and increase the rate of removal of accumulated hydrogen ions from muscles, ultimately delaying the onset of muscle fatigue and improving exercise capacity during high-intensity exercise such as cycling, rowing, and sprinting [9–12].”
BackgroundEnteric-Coated Sodium Bicarbonate Attenuates Gastrointestinal Side-Effects
Hilton, N. P., Leach, N. K., Craig, M. M., Sparks, S. A., & McNaughton, L. R. (2020) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.2019-0151 · Cited by 20 · cited 3× · see citing works
“It can also decrease gastrointestinal discomfort associated with the high oral dose.”
BackgroundMetabolic Alkalosis, Recovery and Sprint Performance
Siegler, J. C., McNaughton, L. R., Midgley, A. W., Keatley, S., & Hillman, A. R. (2010) · International Journal of Sports Medicine · doi:10.1055/s-0030-1261943 · Cited by 19 · cited 1× · see citing works
“…in an attempt to increase the extracellular buffering capacity and increase the rate of removal of accumulated hydrogen ions from muscles, ultimately delaying the onset of muscle fatigue and improving exercise capacity during high-intensity exercise such as cycling, rowing, and sprinting [9–12].”
Backgroundde Oliveira, L. F., Saunders, B., & Artioli, G. G. (2018) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.2017-0394 · Cited by 19 · cited 1× · see citing works
“Recent studies have suggested bariatric surgery as a gastric bypass model [35], as well as gastro-resistant formulations (i.e., embedded [4,36] and enteric-coated capsules [5,36]) to minimize gastrointestinal side effects for a limited duration of time [5,36].”
BackgroundLassen, T., Lindström, L., Lønbro, S., & Madsen, K. (2021) · International Journal of Sport Nutrition and Exercise Metabolism · doi:10.1123/ijsnem.2020-0352 · Cited by 10 · cited 1× · see citing works
“Over the past few decades, many papers have shown that sodium bicarbonate as an ergogenic supplement can enhance people’s performance in various exercises, including running, cycling, rowing, sprinting, and swimming [13–21].”
Background
Flagged first, then by citations
Cited by
Sorted by citations
Huang, D., Wang, X., Takagi, H., Wang, Z., Wang, C., Yang, L., & Huang, B. (2025) · Research in Sports Medicine · doi:10.1080/15438627.2025.2456630 · Cited by 2 · see citing works
“…& Rawson, 1999; Gee, 2016; Huang et al., 2006; Mero et al., 2004), and seven for non-compliance with the participant inclusion criteria (Durkalec-Michalski et al., 2020; Gurton et al., 2023; Jiang et al., 2024; Leach et al., 2023; Miller et al., 2016; Siegler et al., 2016; Tan et al., 2010).”
Fritz, P., Mayer, L., & Maszlag, A. (2025) · Recreation · doi:10.21486/recreation.2025.15.1-2.1
Michalica, T., Březina, J., Polak, M., Mališ, J., Svozil, Z., Plchová, M., Friedecký, D., & Kociánová, E. (2026) · Journal of Human Kinetics · doi:10.5114/jhk/224514
“Perceived exertion (RPE) was evaluated immediately after the 200-m Bi-Fins trial (Ueda and Kurokawa, 1995), while gastrointestinal discomfort was rated ~5 min before the race to detect potential symptoms affecting performance (Jiang et al., 2024).”
Winter, I. P., Sarac, P., & Wilson, P. B. (2026) · European Journal of Sport Science · doi:10.1002/ejsc.70225
“…et al. 2023; W. H. Gurton, Greally, et al. 2023; W. H. Gurton et al. 2024; Hilton, Leach, Craig, et al. 2020; Hilton, Leach, Hilton, et al. 2020; Jiang et al. 2024; Leach et al. 2023; Middlebrook et al. 2021; Shannon et al. 2024, 2026; J. Siegler et al. 2025; W. H. Gurton, Gough, et al. 2025),…”
Influential
- Authors
- Jiang, F.-L., Jeong, D.-H., Eom, S.-H., Lee, H.-M., Cha, B.-J., Park, J.-S., Kwon, R., Nam, J.-Y., Yu, H.-S., Heo, S.-H., Kim, C.-H., & Song, K.-H.
- Affiliations
- National Traditional Sports Teaching and Research Section of Hunan Province, College of Physical Education, Hunan Normal University, Changsha 410012, China
- Soonchunhyang University (KR)
- Seoul National University (KR)
- Department of Pharmaceutical Engineering, College of Medical Sciences, Soonchunhyang University, Asan 31538, Republic of Korea
- Konkuk University (KR)
- Corresponding author
- Song, Keon-Hyoung
- Venue
- Nutrients
- Publisher
- MDPI AG
- Published
- 2024-03-05
- Volume
- 16
- Issue
- 5
- Pages
- 744
- ISSN
- 2072-6643 (ISSN-L)
- PMC
- PMC10933797
- OpenAlex
- W4392471965
- Semantic Scholar
- 38c6315f6a61cd62c3ef8986d280b826ff86a52b
- Cited by
- 4
- References
- 41
- Citations by year
- 2026: 2 · 2025: 2
- FWCI
- 0.58
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Nutrients (publishedVersion, cc-by)
- PubMed (publishedVersion)
- PubMed Central (submittedVersion, cc-by)
- Funders
- Soonchunhyang University Research Fund (2023KT010, 23YBA073)
- Hunan Provincial Sports Bureau Project Fund Key research project 2023–2025 (2023KT010, 23YBA073)
- Hunan Provincial Social Science Fund Project (2023KT010, 23YBA073)
- Topics
- Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmaceutical Science › Drug Solubulity and Delivery Systems
- Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
- Keywords
- sodium bicarbonate, enteric-coated tablets, bicarbonate uptake, gastrointestinal discomfort, high-intensity exercise, tablet formulation, pharmacokinetics
- MeSH terms
- Administration, Oral, Bicarbonates, Biological Availability, Humans, Tablets, Enteric-Coated, Sodium Bicarbonate
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-18.
Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-18.
Cited sources are checked by gpt-6-sol.
Statistics and arithmetic are recomputed, not judged.
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