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Bicarbonate in water

Bicarbonate is the ion behind every claim about alkaline water, and unlike most of those claims it is a real, measurable, labelled figure. This page ranks the waters by bicarbonate per litre, explains what bicarbonate does in the body, and shows what it almost always arrives packaged with.

This is a reference table, not a diagnosis and not a prescription. If a clinician has put you on a sodium, calcium, potassium or fluid restriction, that number comes from them and overrides anything here. Analyses are revised as sources are re-tested, so the label on the bottle you are holding always outranks this page.

The ranking, and what rides along

Read the last two columns together. The pattern is hard to miss: the waters at the top of the bicarbonate list are, with a couple of exceptions, also the ones carrying the most sodium, because a bicarbonate anion in solution needs a cation to balance it and sodium is the one geology supplies most easily.

What bicarbonate actually does

Bicarbonate is the body's main extracellular buffer. Metabolism produces acid continuously — sulphuric acid from the sulphur-containing amino acids in protein, phosphoric acid from phosphate — and bicarbonate is what mops it up before the kidney excretes the remainder. Food carries a net acid or base load depending on its mineral and protein content, which is what the potential renal acid load estimate captures; the PRAL page works through the arithmetic.

Drinking bicarbonate therefore does something real: it adds base to the pool. What it does not do is change your blood pH, which is held between 7.35 and 7.45 by respiration and renal handling and does not drift because of a drink. Claims that alkaline water "alkalises the body" confuse blood with urine — urine pH does move, easily and harmlessly, and by itself that is not a health outcome.

There are two places where the chemistry is genuinely of interest, and both are clinical rather than general. Alkalinisation raises urinary citrate and pH, which is a recognised lever in the management of certain kidney stone types, and that is a clinician's decision with a target and a follow-up test, not a shelf choice. And bicarbonate loading has been studied in high-intensity sport as a buffering aid, at doses far beyond what a bottle of water supplies.

Buying a bicarbonate water sensibly

If you like the taste — and high-bicarbonate waters have a distinctly soft, rounded, slightly soapy character that many people prefer with food — then the only figure worth checking before you make it a daily habit is the sodium. A litre of a 1 800 mg per litre bicarbonate water can bring 400 to 550 mg of sodium with it, which is a quarter of the safe and adequate intake before breakfast. Occasional use is a different question from two litres a day.

Analyses: the figures each producer publishes on the label or in its technical sheet — see the basis line on every water page. Reference intakes: EFSA Dietary Reference Values. Label claims: Directive 2009/54/EC, Annex III. Mineral-water constituent limits and the fluoride labelling rule: Directive 2003/40/EC. Tap-water parametric values: Directive (EU) 2020/2184. Checked 2026-09-06.

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