Sodium carbonates (E500)

What it is

Sodium carbonates are alkaline sodium salts used as raising agents and acidity regulators; baking soda is one ¹²³.

E 500 comprises sodium carbonate, Na₂CO₃ (i); sodium hydrogen carbonate, NaHCO₃ (ii); and sodium sesquicarbonate, Na₂CO₃·NaHCO₃·2H₂O (iii); the INS numbers are the same ⁴¹²⁵. Sodium carbonate, diphosphates and lecithins occurred together in 1,667 French products, mostly biscuits ⁶.

How often it is used

In 2019, 8,587 of 126,556 French packaged foods contained E 500, fourth among additives ⁶.

Of 106,489 NutriNet-Santé adults in 2009–2020, 67.10% consumed it; mean intake was 1267.46 mg/day, 95th percentile 4950 mg/day ⁷.

In the body

Baking soda neutralises stomach acid, and the kidneys regulate the body’s sodium and bicarbonate ⁸⁹¹⁰.

The proximal tubule reclaims about 80% of filtered bicarbonate ¹⁰.

Bicarbonate reclamation in the proximal tubuleProximal tubule lumen, epithelial cell and peritubular interstitium

Filtered HCO3− + secreted H+
Carbonic anhydrase IV (CA4), GPI-anchored on the apical membraneZn2+H+ enters the lumen mainly via NHE3 (SLC9A3), 1:1 for Na+, and the V-ATPase
Luminal CO2 + H2O
Non-enzymatic diffusion across the apical membraneAquaporin 1 may conduct part of the CO2 (preliminary data)
Cytosolic CO2 + H2O
Carbonic anhydrase II (CA2)Zn2+The H+ formed is secreted into the lumen again
Cytosolic HCO3−
Electrogenic Na+/HCO3− cotransporter NBCe1-A (SLC4A4), basolateralExports 1 Na+ with 3 HCO3− equivalents
Interstitial HCO3−

What studies show

Bicarbonate tablets did not improve physical function in older people with advanced kidney disease ¹¹.

BiCARB randomised 300 adults aged 60 or over, with eGFR below 30 mL/min/1.73 m² and serum bicarbonate below 22 mmol/L, to up to 3 g/day or placebo; mean follow-up was 16.4 months ¹¹. The 12-month physical performance score differed by −0.4 points with bicarbonate (95% CI −0.9 to 0.1) ¹¹. 131 of 152 participants on bicarbonate had 457 adverse events; 132 of 148 on placebo had 400 ¹¹.

JECFA’s acceptable daily intake is “not limited” for sodium carbonate and hydrogen carbonate, provided cation intake is considered ¹²¹².

Regulation

All four jurisdictions permit sodium carbonate and baking soda ^1819203.

Jurisdiction	Rule
European Union	Group I, quantum satis ¹⁸
United States	Generally recognised as safe; sesquicarbonate only in cream ¹⁹
Japan	Sodium carbonate and bicarbonate designated ²⁰
China	Carbonate and bicarbonate as needed outside listed foods; sesquicarbonate only in pastries, biscuits and goat milk ³

References

Regulator
Joint FAO/WHO Expert Committee on Food Additives. Sodium carbonate: summary of evaluations performed by the Joint FAO/WHO Expert Committee on Food Additives IPCS INCHEM, JECFA evaluations, entry dated 9 March 2003, 2003.
https://inchem.org/documents/jecfa/jeceval/jec_2137.htm
Funding and finding
Funding
Food and Agriculture Organization of the United Nations and World Health Organization; summary hosted by the International Programme on Chemical Safety.
Finding
INS 500i. Chemical names: sodium carbonate; sodium salt of carbonic acid. Synonym: soda ash. Functional class: alkali. Latest evaluation 1965; ADI not limited. Report NMRS 40/TRS 339-JECFA 9/16; toxicological monograph FAS 67.29/NMRS 40A,B,C-JECFA 9/154; specifications Compendium Addendum 10/FNP 52 Add.10/34 (metals limits) (2002).
Regulator
Joint FAO/WHO Expert Committee on Food Additives. Sodium hydrogen carbonate: summary of evaluations performed by the Joint FAO/WHO Expert Committee on Food Additives IPCS INCHEM, JECFA evaluations, entry dated 9 March 2003, 2003.
https://inchem.org/documents/jecfa/jeceval/jec_2151.htm
Funding and finding
Funding
Food and Agriculture Organization of the United Nations and World Health Organization; summary hosted by the International Programme on Chemical Safety.
Finding
INS 500ii. Chemical names: sodium hydrogen carbonate; sodium acid carbonate. Synonyms: baking soda; bicarbonate of soda; sodium bicarbonate. Functional class: alkali; leavening agent; buffer. Latest evaluation 1965; ADI not limited. Report NMRS 40/TRS 339-JECFA 9/16; toxicological monograph FAS 67.29/NMRS 40A,B,C-JECFA 9/155; specifications Compendium Addendum 10/FNP 52 Add.10/34 (metals limits) (2002).
Regulator
National Health Commission of the People's Republic of China; State Administration for Market Regulation. 食品安全国家标准食品添加剂使用标准 (National food safety standard: Standard for uses of food additives), GB 2760—2024 National standard of the People's Republic of China, issued 8 February 2024, in force from 8 February 2025, replacing GB 2760—2014, 2024.
https://file.jgvogel.cn/134/upload/resources/file/595476.pdf
Funding and finding
Funding
Issued by the National Health Commission and the State Administration for Market Regulation; the standard carries no funding statement. The text was read in a copy hosted by a third party, as the issuing bodies' sites refused automated access; its title page, contents and Table A.1 are those of GB 2760—2024.
Finding
Table A.1, ascorbic acid (vitamin C), CNS 04.014, INS 300, functions flour treatment agent and antioxidant: used in various foods in appropriate amounts according to production needs (按生产需要适量使用), except the food categories numbered 1 to 5, 10 to 62 and 68 in Table A.2, which comprise milks, fermented milk, milk powder and cream, butter, fresh fruit, vegetables, fungi and algae, cereals, rice, flours and raw noodles, fresh meat, aquatic products, eggs, sugars, honey, salt, spices, infant formulae and complementary foods for infants, drinking waters, fruit and vegetable juices, tea and coffee; maximum 5.0 g/kg in peeled or pre-cut fresh fruit (04.01.01.03) and in peeled, cut or shredded vegetables (04.02.01.03), 0.2 g/kg in wheat flour (06.03.01) and 1.5 g/kg in fruit and vegetable juices (14.02.01), as ready to drink. Table A.1, sodium carbonate (碳酸钠, CNS 01.302, INS 500(i)), function acidity regulator: according to production needs in various foods except categories 1 to 30 and 33 to 68 in Table A.2, and in fermented rice products; categories 31 and 32 are raw wet and raw dry noodle products. Sodium hydrogen carbonate (碳酸氢钠, CNS 06.001, INS 500(ii)), functions raising agent, acidity regulator and stabiliser: according to production needs in various foods except categories 1 to 56 and 58 to 68 in Table A.2, and in fermented rice products; category 57 is cereal-based complementary foods for infants and young children. Sodium sesquicarbonate (碳酸氢三钠, also named 倍半碳酸钠, CNS 01.305, INS 500(iii)), function acidity regulator: according to production needs in dairy products other than listed exceptions, only goat milk, and in pastries (07.02) and biscuits (07.03). Table A.1, phospholipids (磷脂, CNS 04.010, INS 322), functions antioxidant and emulsifier: according to production needs in various foods, except the categories numbered 1 to 4, 6, 8 to 53 and 59 to 68 in Table A.2, which comprise pasteurised and sterilised milk, fermented milk, milk and cream powder, vegetable oil, animal fats, butter, fresh fruit, vegetables, fungi and algae, cereals, rice, flours and noodle products, fresh, chilled and frozen meat, aquatic products, eggs, sugars, honey, salt, spices, drinking waters, fruit and vegetable juices, wines, and tea and coffee; cream (category 5), hydrogenated vegetable oil (7) and infant formulae and complementary foods for infants (54 to 58) are not among the exceptions. Table A.1, mono- and diglycerides of fatty acids (单,双甘油脂肪酸酯, CNS 10.006, INS 471), functions emulsifier and coating agent (乳化剂、被膜剂): according to production needs in various foods, except the 59 categories numbered 1 to 4, 6 to 11, 13 to 14, 16 to 30, 32 to 53 and 59 to 68 in Table A.2; cream (5), surface-treated fresh fruit (12) and vegetables (15), raw wet noodle products (31) and infant formulae and complementary foods for infants (54 to 58) are not among the exceptions; maximum 20.0 g/kg in butter and concentrated butter (02.02.01.01), 30.0 g/kg in raw dry noodle products (06.03.02.02), 6.0 g/kg in brown sugar, raw sugar, other sugars and syrups (11.01.02) and 5.0 g/kg in spices (12.09). Table A.1, phosphoric acid and phosphates (磷酸及磷酸盐), a group entry that includes disodium dihydrogen pyrophosphate (焦磷酸二氢二钠), tetrasodium pyrophosphate (焦磷酸钠), tetrapotassium pyrophosphate (焦磷酸四钾), trisodium monohydrogen diphosphate (焦磷酸一氢三钠) and calcium acid pyrophosphate (酸式焦磷酸钙); its INS numbers include 450(i), 450(ii), 450(iii), 450(v) and 450(vii); functions water-retention agent, raising agent, acidity regulator, stabiliser, coagulant and anticaking agent (水分保持剂、膨松剂、酸度调节剂、稳定剂、凝固剂、抗结剂). Maximum levels apply singly or in combination, expressed as phosphate (PO4 3-), for example 5.0 g/kg in dairy products other than listed exceptions, 15.0 g/kg in bakery wares (07.0), 5.0 g/kg in prepared and cooked meat products, 20.0 g/kg in non-dairy creamer and compound seasonings and 80.0 g/kg in seasoning packets for instant wet noodles (12.10.01.03); in infant formulae (13.01.01, 13.01.02) and complementary foods for infants and young children (13.02), 1.0 g/kg using only calcium hydrogen phosphate and sodium dihydrogen phosphate.
Regulator
European Commission. Commission Regulation (EU) No 231/2012 of 9 March 2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 of the European Parliament and of the Council Official Journal of the European Union, L 83, 22 March 2012, p. 1, 2012.
https://eur-lex.europa.eu/eli/reg/2012/231/oj
Funding and finding
Funding
European Commission.
Finding
E 500 (i) sodium carbonate, synonym soda ash: Na2CO3·nH2O (n = 0, 1 or 10), molecular weight 106.00 (anhydrous), not less than 99% Na2CO3 on the anhydrous basis. E 500 (ii) sodium hydrogen carbonate, synonyms sodium bicarbonate, sodium acid carbonate, bicarbonate of soda, baking soda: NaHCO3, molecular weight 84.01, not less than 99% on the anhydrous basis, pH 8.0 to 8.6 in 1% solution. E 500 (iii) sodium sesquicarbonate, chemical name sodium monohydrogen dicarbonate: Na2CO3·NaHCO3·2H2O, molecular weight 226.03, 35.0 to 38.6% NaHCO3 and 46.4 to 50.0% Na2CO3, sodium chloride not more than 0.5%. For all three: arsenic not more than 3 mg/kg, lead not more than 2 mg/kg, mercury not more than 1 mg/kg.
Regulator
Joint FAO/WHO Expert Committee on Food Additives. Sodium sesquicarbonate: summary of evaluations performed by the Joint FAO/WHO Expert Committee on Food Additives IPCS INCHEM, JECFA evaluations, entry dated 9 March 2003, 2003.
https://inchem.org/documents/jecfa/jeceval/jec_2172.htm
Funding and finding
Funding
Food and Agriculture Organization of the United Nations and World Health Organization; summary hosted by the International Programme on Chemical Safety.
Finding
INS 500iii. Chemical name: sodium sesquicarbonate. Synonym: sodium monohydrogendicarbonate. Functional class: alkali; buffering agent. Latest evaluation 1981; ADI not specified, included in the group ADI for carbonates and bicarbonates. Report TRS 669-JECFA 25/33; toxicological monograph not prepared.
Independent research
Chazelas E, Deschasaux M, Srour B, Kesse-Guyot E, Julia C, Alles B, et al. Food additives: distribution and co-occurrence in 126,000 food products of the French market Scientific Reports, 2020.
doi:10.1038/s41598-020-60948-w PubMed 32132606
Funding and finding
Funding
PhD grant from Paris 13 University (E. Chazelas); post-doctoral fellowship from the Fondation pour la Recherche Médicale (ARF201809007046, M. Deschasaux); French Ministry of Health (DGS Arrêté 29 Novembre 2019); French National Cancer Institute (INCa_14059); European Research Council (ERC CoG ADDITIVES_864219). Researchers were independent from funders. Funders had no role in the study design, the collection, analysis, and interpretation of data, the writing of the report, and the decision to submit the article for publication. Open Food Facts is a non-profit association.
Finding
53.8% of products contained at least one additive and 11.3% five or more. Appendix 7, products containing each additive: citric acid E 330 18,302; lecithins E 322 13,102; E 14XX modified starches 10,100; sodium carbonates E 500 8587; ascorbic acid E 300 7919; xanthan gum E 415 7327; sodium nitrite E 250 7144; diphosphates E 450 6529; pectins E 440 6504; mono- and diglycerides of fatty acids E 471 6060. Specific starches: E 1442 209, E 1422 173, E 1414 55, E 1450 30, E 1412 27, E 1420 19, E 1404 18, E 1440 5, E 1410 1. The footnote and the Discussion state that the number of products containing each specific modified starch may be underestimated because packaging often states only 'modified starch'. E 500 had the highest squared loading (0.64) in cluster 3, 'stabilizers and emulsifiers mostly used in biscuits and cakes'; sodium carbonate (E 500), diphosphates (E 450) and lecithins (E 322) co-occurred in 1667 products, mostly biscuits. The authors describe E 500, E 450, E 503 and E 422 as widely used in biscuits and cakes as acidity regulators, stabilizers and emulsifiers. Additive doses were not available.
Independent research
Chazelas E, Druesne-Pecollo N, Esseddik Y, de Edelenyi FS, Agaesse C, De Sa A, et al. Exposure to food additive mixtures in 106,000 French adults from the NutriNet-Santé cohort Scientific Reports, 2021.
doi:10.1038/s41598-021-98496-6 PubMed 34608173
Funding and finding
Registration
NCT03335644
Participants
106,489
Funding
NutriNet-Santé: Ministère de la Santé, Santé Publique France, INSERM, INRAE, CNAM and University Sorbonne Paris Nord. E. Chazelas: doctoral funding from University Sorbonne Paris Nord; C. Debras: French National Cancer Institute. Project: European Research Council (Horizon 2020, grant agreement No 864219), French National Cancer Institute (INCa_14059), French Ministry of Health (arrêté 29.11.19) and IdEx Université de Paris (ANR-18-IDEX-0001). Researchers were independent from funders; funders had no role in the study design, the collection, analysis and interpretation of data, the writing of the report, and the decision to submit the article for publication.
In-kind support
Some of the 2677 ad hoc laboratory assays of additive doses were ordered by the consumers' association UFC Que Choisir.
Finding
Intakes of 90 additives were estimated from repeated 24-h records matched to brand-level composition data (OQALI, Open Food Facts, Mintel GNPD), with doses from 2677 laboratory assays, EFSA dose data by food category or Codex GSFA levels; descriptive analyses were weighted to the 2016 French census. Table 1, % consumers; median, 95th percentile and mean (SD) in mg/day; mean (SD) in mg/kg bw/day: modified starches E 14xx 91.48%; 1304.66, 4270.38, 1596.45 (1394.44); 24.33 (21.84). Citric acid E 330 91.15%; 1380.84, 6193.84, 1956.51 (2231.41); 29.84 (34.31). Lecithins E 322 86.57%; 35.36, 168.33, 53.94 (71.99); 0.83 (1.1). Xanthan gum E 415 79.74%; 303.60, 1401.31, 439.26 (508.65); 6.62 (7.62). Mono- and diglycerides of fatty acids E 471 78.07%; 101.90, 547.24, 160.8 (197.42); 2.44 (2.98). Sodium carbonates E 500 67.10%; 560.00, 4950.00, 1267.46 (1913.51); 19.62 (29.73), with median 8.51 and 95th percentile 76.73 mg/kg bw/day. The ADI column reads NA for all six. Diphosphates E 450 64.36%; 62.86, 715.67, 178.33 (308.05); 2.74 (4.67); ADI 40 mg/kg bw/day, exceeded by 0.02% of all participants and 0.03% of consumers. Additives without a specified ADI can be used quantum satis, that is with no limitations other than current good manufacturing practice. The authors state that information on the health impact of regular and cumulative intake of food additives in humans, and on effects of their mixtures, is still missing.
Regulator
US Food and Drug Administration. Part 331—Antacid products for over-the-counter (OTC) human use, 21 CFR part 331 Code of Federal Regulations, title 21, part 331, read in the electronic Code of Federal Regulations, edition of 1 October 2026, 2026.
https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-331
Funding and finding
Funding
US Food and Drug Administration; the text is federal regulation codified by the Office of the Federal Register.
Finding
An OTC antacid is generally recognized as safe and effective if each active ingredient contributes at least 25% of the total acid neutralizing capacity and the product contains at least 5 mEq of acid neutralizing capacity (section 331.10). Section 331.11(k)(1): sodium bicarbonate, or carbonate as a component of an effervescent preparation, with a maximum daily dosage limit of 200 mEq of sodium for persons up to 60 years old and 100 mEq of sodium for persons 60 years or older, and 200 and 100 mEq of bicarbonate ion respectively. Section 331.30(c)(1): labels warn not to take more than the maximum recommended daily dosage in a 24-hour period, or use the maximum dosage for more than 2 weeks, except under the advice and supervision of a physician.
Independent research
Palmer LG, Schnermann J. Integrated control of Na transport along the nephron Clinical Journal of the American Society of Nephrology, 2015.
doi:10.2215/CJN.12391213 PubMed 25098598
Funding and finding
Funding
L.G. Palmer: National Institutes of Health grant R01-DK27847. J. Schnermann: Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases.
Finding
Review. More than 500 g of sodium is filtered daily; under most conditions the kidneys excrete more than 95% of ingested sodium. The proximal tubule reabsorbs 60-70% (apical NHE3 the main mechanism), the ascending loop of Henle, mostly the thick limb, 25-30% (NKCC2 and NHE3), and the distal convoluted tubule and collecting ducts no more than 5-10%, through thiazide-sensitive NCC (early DCT) and amiloride-sensitive ENaC (late DCT, connecting tubule, collecting duct); distal reabsorption is the regulated part. Two-thirds or more of renal oxygen uptake is spent on the Na,K-ATPase. With plausible tenfold changes in intake, fractional reabsorption varies between about 97% and 99.7%. Sodium depletion increases ENaC activity, an effect mimicked by aldosterone. Potassium loading lowers NCC phosphorylation and abundance and raises ENaC activity, shifting sodium reabsorption to segments where principal cells secrete K+ in exchange for Na+. Changes in body Na content and blood volume are the likely cause of the relation between Na intake and blood pressure.
Independent research
Skelton LA, Boron WF, Zhou Y. Acid-base transport by the renal proximal tubule Journal of Nephrology, 2010.
PubMed 21170887
Funding and finding
Funding
US National Kidney Foundation Fellowship (FLB795) to L.A.S.; US National Institutes of Health grants P01-DK17433 and R01-DK081567 to W.F.B.; American Heart Association Scientist Development Grant 0735432N to Y.Z.
Finding
Narrative review. The kidneys filter some 4,300 mmol of HCO3- a day; the proximal tubule reclaims about 80% and distal segments nearly all of the remainder. Proximal-tubule cells secrete H+ mainly through the Na-H exchanger NHE3, which exchanges 1 H+ for 1 Na+, and through the vacuolar H+-ATPase. Carbonic anhydrase IV, GPI-anchored to the outer leaflet of the apical membrane, converts secreted H+ and luminal HCO3- to CO2 and H2O, which re-enter the cell, in part through aquaporin 1 according to preliminary data. Cytosolic carbonic anhydrase II, about 95% of renal carbonic anhydrase activity, converts CO2 and H2O back to HCO3- and H+; HCO3- exits with Na+ across the basolateral membrane through the electrogenic cotransporter NBCe1-A at a stoichiometry of 3:1. Increases in basolateral HCO3- lower HCO3- reabsorption in isolated perfused proximal tubules, and HCO3- infusion in rats lowers it on free-flow micropuncture.
Independent research
BiCARB study group, Witham MD, Band M, Ahmed A, Almond MK, Balasubramaniam G, et al. Clinical and cost-effectiveness of oral sodium bicarbonate therapy for older patients with chronic kidney disease and low-grade acidosis (BiCARB): a pragmatic randomised, double-blind, placebo-controlled trial BMC Medicine, 2020.
doi:10.1186/s12916-020-01542-9 PubMed 32268897
Funding and finding
Registration
ISRCTN09486651; EudraCT 2011-005271-16
Participants
300
Follow-up
up to 2 years; mean 16.4 months (median 24 months in both arms); primary outcome at 12 months
Funding
National Institute for Health Research Health Technology Assessment programme (project reference 10/71/01). The funder had input into the study design via the original commissioning call specification and no other role in study design, data collection, data analysis, data interpretation or writing of the report.
Finding
Sodium bicarbonate 500 mg three times daily, raised to 1 g three times daily if serum bicarbonate remained below 22 mmol/L at 3 months, or matching placebo. Short Physical Performance Battery at 12 months 8.3 (SD 2.5) against 8.8 (SD 2.2) points; adjusted treatment effect -0.4 (95% CI -0.9 to 0.1, p = 0.15), with primary outcome data for 187 participants. eGFR effect 0.6 mL/min/1.73 m2 (-0.8 to 2.0); systolic blood pressure effect 0 mmHg (-4 to 3); serum bicarbonate 1.7 mmol/L higher at 3 months (1.0 to 2.4). 457 adverse events with bicarbonate against 400 with placebo; at least one adverse event in 131 of 152 (86.1%) against 132 of 148 (89.1%); deaths 15 against 11 (HR 1.30, 0.60 to 2.83). Placebo dominated bicarbonate in cost-effectiveness analyses.
Regulator
Joint FAO/WHO Expert Committee on Food Additives. Toxicological evaluation of some antimicrobials, antioxidants, emulsifiers, stabilizers, flour-treatment agents, acids and bases FAO Nutrition Meetings Report Series 40A,B,C; WHO/Food Add./67.29; ninth (Rome, 13 to 20 December 1965) and tenth (Geneva, 11 to 18 October 1966) meetings; entries for carbonates, hydroxides and oxides, 1967.
https://inchem.org/documents/jecfa/jecmono/40abcj46.htm
Funding and finding
Funding
Food and Agriculture Organization of the United Nations and World Health Organization.
Finding
Sodium carbonate (Na2CO3·xH2O, not less than 99.0% Na2CO3 after drying) is used as a neutralizing agent; sodium hydrogen carbonate (NaHCO3, baking soda, not less than 99.0% after drying) as a neutralizing and leavening agent. Evaluation covering these and the other listed carbonates, hydroxides and oxides: 'Provided the nutritional implications or the over-all dietary intake of cations derived from these additives are taken into account, there appear to be no toxicological grounds to limit their use in accordance with good manufacturing practice.'
Industry-funded
Kurtz TW, Al-Bander HA, Morris RC Jr. "Salt-sensitive" essential hypertension in men. Is the sodium ion alone important? New England Journal of Medicine, 1987.
doi:10.1056/NEJM198710223171702 PubMed 3309653
Funding and finding
Participants
5
Follow-up
7 days for each sodium salt
Funding
Supported by the General Clinical Research Center, University of California, San Francisco, with funds provided by grants (RR-00079, RO1-AM-32631 and RO1-HL-37696) from the National Institutes of Health, generous gifts from the Church and Dwight Corporation and the Emil Mosbacher, Jr., Foundation, and grants from the National Dairy Board administered in cooperation with the National Dairy Council and the Research Evaluation and Allocation Committee of the University of California, San Francisco. Dr. Kurtz is the recipient of a Public Health Service Clinical Investigator Award (HL-01490) from the National Heart, Lung, and Blood Institute.
Finding
Sodium chloride 240 mmol per day (5.52 g sodium) for 7 days raised systolic and diastolic blood pressure by 16 ± 2 and 8 ± 2 mm Hg (mean ± SEM, P < 0.05); an equimolar amount of sodium as sodium citrate induced no change, and replacing supplemental sodium chloride with sodium citrate abolished the rise. Both salts induced comparable sodium retention, weight gain and suppression of plasma renin activity and aldosterone; sodium chloride, but not sodium citrate, increased plasma volume and urinary calcium excretion. The authors call the findings preliminary and state that they require confirmation in larger numbers of patients of both sexes.
Expert consensus
World Health Organization. Guideline: sodium intake for adults and children World Health Organization, 2012.
PubMed 23658998
Funding and finding
Funding
WHO acknowledges financial support from the Ministry of Health, Labour and Welfare of the Government of Japan, the Korea Food and Drug Administration, the Korea Health Industry Development Institute and the International Kidney Evaluation Association Japan.
Finding
WHO recommends a reduction in sodium intake to reduce blood pressure and risk of cardiovascular disease, stroke and coronary heart disease in adults, and a reduction to less than 2 g/day sodium (5 g/day salt) in adults (strong recommendation); in children, a reduction to control blood pressure, with the adult maximum adjusted downward for energy requirements (strong recommendation).
Regulator
EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, Castenmiller J, de Henauw S, Hirsch-Ernst KI, Kearney J, et al. Dietary reference values for sodium EFSA Journal, 2019.
doi:10.2903/j.efsa.2019.5778 PubMed 32626425
Funding and finding
Funding
European Food Safety Authority, on request from the European Commission (question number EFSA-Q-2011-01224).
Finding
Sodium chloride is the main constituent of table salt; 1 g of sodium chloride provides 0.4 g of sodium and 0.6 g of chloride. In healthy people almost all dietary sodium is absorbed, along most of the small and large intestine; apical co-transporters couple sodium entry to the uptake of solutes, the basolateral Na+/K+-ATPase exchanges three intracellular Na+ for two extracellular K+, net sodium and water absorption occurs in the distal ileum and colon, and distal absorption responds to aldosterone. Renin is released from the juxtaglomerular apparatus in response to reduced afferent arteriolar pressure, increased sympathetic activity and decreased distal tubular NaCl; renin hydrolyses angiotensinogen to angiotensin I, which angiotensin-converting enzyme converts to angiotensin II; angiotensin II stimulates proximal sodium reabsorption, arteriolar constriction and adrenal aldosterone release; aldosterone stimulates sodium recovery in exchange for potassium in distal tubule, collecting ducts and distal colon. Genotypes with increased ENaC function cause volume expansion, hypertension and hypokalaemia (e.g. Liddle's syndrome). A sodium intake of 2.0 g/day is considered safe and adequate for adults, including pregnant and lactating women.
Funding unknown
Luft FC, Zemel MB, Sowers JA, Fineberg NS, Weinberger MH. Sodium bicarbonate and sodium chloride: effects on blood pressure and electrolyte homeostasis in normal and hypertensive man Journal of Hypertension, 1990.
doi:10.1097/00004872-199007000-00010 PubMed 2168457
Funding and finding
Participants
20
Follow-up
7 days on each regimen, crossover one month apart
Funding
Not read: the publisher offers the article only as a subscriber PDF. PubMed lists grant RR 00750 (NCRR, NIH) and the publication types Research Support, U.S. Gov't, P.H.S. and Research Support, Non-U.S. Gov't.
Finding
Randomly allocated, placebo-controlled crossover trial. After 4 days of balance, participants drank 3 L/day of a NaHCO3-containing mineral water (26.2 mmol/L sodium, 33.03 mmol/L HCO3) or a control solution with equimolar cations as chloride salts for 7 days (total sodium 138 mmol/day). NaCl did not influence blood pressure, whereas NaHCO3 decreased systolic blood pressure by 5 mmHg in the hypertensive subjects. Both regimens decreased plasma renin activity in the hypertensive subjects. Urinary calcium excretion increased consistently with NaCl but not with NaHCO3; urate excretion was not influenced.
Funding unknown
Al-Abri SA, Kearney T. Baking soda misuse as a home remedy: case experience of the California Poison Control System Journal of Clinical Pharmacy and Therapeutics, 2014.
doi:10.1111/jcpt.12113 PubMed 24313600
Funding and finding
Participants
192
Follow-up
Retrospective review of cases reported from 2000 to 2012
Funding
Not read: the full text is restricted to subscribers; only the abstract page was read, in an Internet Archive copy.
Finding
Of 192 cases, the most common reasons for misuse were antacid use (60.4%), attempts to 'beat a urine drug test' (11.5%) and treatment of urinary tract infection (4.7%). 55.2% had significant symptoms warranting medical evaluation; 12 patients required hospital admission and developed electrolyte imbalances, metabolic alkalosis or respiratory depression.
Regulator
European Commission. Commission Regulation (EU) No 1129/2011 of 11 November 2011 amending Annex II to Regulation (EC) No 1333/2008 of the European Parliament and of the Council by establishing a Union list of food additives Official Journal of the European Union, L 295, 12 November 2011, p. 1, 2011.
https://eur-lex.europa.eu/eli/reg/2011/1129/oj
Funding and finding
Funding
European Commission.
Finding
Annex II, Part C, Group I lists E 500 sodium carbonates with the specific maximum level quantum satis. E 500 is also listed at quantum satis in individual food categories, including soured cream butter and salt, and 'only as rising agent' in processed cereal-based foods and baby foods for infants and young children.
Regulator
US Food and Drug Administration. Sodium bicarbonate, sodium carbonate and sodium sesquicarbonate, 21 CFR 184.1736, 184.1742 and 184.1792: direct food substances affirmed as generally recognized as safe Code of Federal Regulations, title 21, part 184, read in the electronic Code of Federal Regulations, edition of 1 October 2026, 2026.
https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-184
Funding and finding
Funding
US Food and Drug Administration; the text is federal regulation codified by the Office of the Federal Register.
Finding
Part 184 lists direct food substances affirmed as generally recognized as safe (GRAS), in these sections affirmed at 48 FR 52442 to 52443, 18 November 1983. Sodium bicarbonate (NaHCO3, CAS 144-55-8, section 184.1736) and sodium carbonate (Na2CO3, CAS 497-19-8, section 184.1742) are used in food with no limitation other than current good manufacturing practice; sodium carbonate as antioxidant, curing and pickling agent, flavoring agent and adjuvant, pH control agent and processing aid. Sodium sesquicarbonate (Na2CO3·NaHCO3·2H2O, CAS 533-96-0, section 184.1792) is used as a pH control agent in cream, at a level sufficient to control lactic acid before pasteurization and churning of cream into butter. Each ingredient meets the specifications of the Food Chemicals Codex, 3rd edition (1981).
Regulator
The Japan Food Chemical Research Foundation. List of Designated Food Additives The Japan Food Chemical Research Foundation; English list of the designated food additives in Appended Table 1 of the Enforcement Regulations under the Food Sanitation Act, as of 1 March 2024, 2024.
https://www.ffcr.or.jp/en/tenka/lists-of-additives/list-of-designated-additives.html
Funding and finding
Funding
Published by the Japan Food Chemical Research Foundation, which translated the substance names from the original Japanese table; the English page of the Consumer Affairs Agency on food additives links to this list as its List of Designated Additives.
Finding
Designated additives are those designated by the Prime Minister (by the Minister of Health, Labour and Welfare until March 2024) under Article 12 of the Food Sanitation Act as unlikely to harm human health; 476 in total as of 1 March 2024. The list includes No. 251 Sodium Bicarbonate (Sodium Hydrogen Carbonate or Bicarbonate Soda) and No. 252 Sodium Carbonate (Crystal: Carbonate Soda, Anhydrous: Soda Ash). It also includes No. 341 Potassium Pyrophosphate (Tetrapotassium Pyrophosphate), No. 342 Calcium Dihydrogen Pyrophosphate (Acid Calcium Pyrophosphate), No. 343 Disodium Dihydrogen Pyrophosphate (Acid Disodium Pyrophosphate) and No. 345 Sodium Pyrophosphate (Tetrasodium Pyrophosphate), besides No. 344 Ferric Pyrophosphate.

Updated 2026-10-21