Potassium citrate and calcium balance in older adults
What it found
In 52 older men and women, taking potassium citrate for 6 months lowered urine calcium and improved calcium balance at the higher dose.
It did not change how much calcium was absorbed from the gut.
What they found
Studies in people
Urine calcium
At 6 months, 24-hour urine calcium dropped by 46 mg/day in the 60 mmol group and by 59 mg/day in the 90 mmol group, compared with placebo. The difference between the two doses was not significant.
Calcium balance
Net calcium balance improved significantly in the 90 mmol group (142 mg/day) compared with placebo (-80 mg/day). The 60 mmol group also improved (33 mg/day) but this did not reach statistical significance.
Calcium absorption
Potassium citrate did not change the fraction of calcium absorbed from the gut at either dose.
Bone resorption marker
A blood marker of bone breakdown (CTX) fell significantly in both potassium citrate groups compared with placebo. The marker of bone formation (bsALP) did not change.
Acid neutralization
Net acid excretion became negative in both treatment groups, meaning the dietary acid was fully neutralized. It was -11.3 mmol/day on 60 mmol and -29.5 mmol/day on 90 mmol, compared with 16.1 mmol/day on placebo.
Tolerance and safety
No participant left the study because of stomach upset. One participant developed mild high blood potassium at a dose of 40 mmol/day and was withdrawn; potassium levels returned to normal after stopping the supplement.
What the authors conclude
“Readily available, safe, and easily administered in an oral form, potassium citrate has the potential to improve skeletal health.”
Also in their conclusions
- They conclude that potassium citrate has a long-term positive effect on calcium balance by reducing urine calcium without affecting gut absorption.
- They state that "potassium citrate has the potential to improve skeletal health" and call for longer trials with bone density and fracture outcomes.
- They advise that serum potassium should be monitored when increasing the dose of alkaline salts.
How it was done
The typical Western diet creates a mild acid load that may pull calcium from bones. The authors wanted to see whether neutralizing this acid with potassium citrate would improve calcium balance over the longer term.
They randomly assigned 52 healthy men and women over age 55 to take potassium citrate 60 mmol/day, 90 mmol/day, or a placebo for 6 months. Everyone also took calcium citrate and vitamin D3. Calcium balance, urine calcium, and bone turnover markers were measured at the start and at 6 months.
What it can’t tell you
- This was a 6-month study, so it cannot show whether the changes in calcium balance lead to better bone density or fewer fractures over time.
- The study was small and included mostly Caucasian women, so the results may not apply to all older adults.
- The effects in people with lower urine calcium at the start cannot be determined from this study.
Who paid
- Funding
- Funded by NIAMS NIH HHS; NCRR NIH HHS (from the PubMed record).
- Authors work at
- Johns Hopkins University, USA
The paper
- Title
- Potassium citrate supplementation results in sustained improvement in calcium balance in older men and women
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Moseley KF, Weaver CM, Appel L, Sebastian A, Sellmeyer DE (2013). Potassium citrate supplementation results in sustained improvement in calcium balance in older men and women. Journal of bone and mineral research. doi:10.1002/jbmr.1764Free full textPubMed 22991267DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error