Randomised trial · The British journal of nutrition · 2009Abstract only

Potassium citrate and bone markers in young women

What it found

In a small trial in young women, potassium citrate lowered a marker of bone breakdown and raised calcium retention.

Both calcium supplements lowered parathyroid hormone.

What they found

Studies in people

Bone breakdown marker

Potassium citrate lowered the bone resorption marker N-terminal telopeptide of type I collagen compared with the control session.

Calcium retention

Potassium citrate raised calcium retention relative to the control session.

Parathyroid hormone

Both calcium carbonate and calcium citrate lowered serum parathyroid hormone concentration.

Calcium and bone breakdown

Both calcium supplements lowered bone resorption compared with the control session, but this was significant only for calcium carbonate.

Bone formation marker

No differences in the bone formation marker bone-specific alkaline phosphatase were seen among the study sessions.

What the authors conclude

“The results suggest that potassium citrate has a positive effect on the resorption marker despite low Ca intake.”
Karp HJ, Ketola ME, Lamberg-Allardt CJ, 2009

Also in their conclusions

  • They suggest that potassium citrate has a positive effect on the resorption marker despite low calcium intake.
  • They report that both calcium supplements were absorbed well and decreased parathyroid hormone efficiently.

How it was done

Potassium and calcium supplements may each help bone in different ways. Potassium citrate may work by balancing the acid load from a high protein diet or low intake of fruits and vegetables.

Twelve healthy women aged 22 to 30 took part in four 24-hour study sessions, each acting as her own control. In each session they took a single dose of calcium carbonate, calcium citrate, potassium citrate or a placebo, with the same diet containing 300 mg calcium.

What it can’t tell you

  • We summarised it from the abstract only.
  • This was a short trial with a single dose in each session, so it cannot show the effects of taking these supplements over a longer period.
  • The study was in young women only, so the results may not apply to other groups.

The paper

Title
Acute effects of calcium carbonate, calcium citrate and potassium citrate on markers of calcium and bone metabolism in young women
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Abstract only
Cite
Karp HJ, Ketola ME, Lamberg-Allardt CJ (2009). Acute effects of calcium carbonate, calcium citrate and potassium citrate on markers of calcium and bone metabolism in young women. The British journal of nutrition. doi:10.1017/S0007114509990195PubMed 19538811DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error