Meta-analysis of calcium bioavailability: A comparison of calcium citrate with calcium carbonate

Khashayar Sakhaee, Taft Bhuket, Beverley Adams-Huet, D. Sudhaker Rao

Research output: Contribution to journalArticlepeer-review

72 Scopus citations


Objective. To perform a meta-analysis of data from available published trials comparing the bioavailability of calcium carbonate with that of calcium citrate. Data sources. The whole set was comprised of 15 studies involving 184 subjects who underwent measurement of calcium absorption from calcium carbonate and calcium citrate. Category A excluded four studies for lack of physiological relevance, use of a mixed preparation with low content of calcium carbonate, or wide variability in results. Category B was comprised of five studies (from Category A) involving 71 subjects who took calcium supplements on an empty stomach. Category C was comprised of six studies (from Category A) involving 65 subjects who took calcium preparations with meals. Method. The meta-analysis of calcium absorption data from calcium carbonate and calcium citrate, with calculation of effect size and 95% confidence intervals. Results. Calcium absorption from calcium citrate was consistently significantly higher than that from calcium carbonate by 20.0% in the whole set, by 24.0% in Category A, by 27.2% on an empty stomach, and by 21.6% with meals. Conclusion. Calcium citrate is better absorbed than calcium carbonate by approximately 22% to 27%, either on an empty stomach or co-administered with meals.

Original languageEnglish (US)
Pages (from-to)313-321
Number of pages9
JournalAmerican Journal of Therapeutics
Issue number6
StatePublished - Nov 1999


  • Calcium absorption
  • Calcium carbonate
  • Calcium citrate

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)


Dive into the research topics of 'Meta-analysis of calcium bioavailability: A comparison of calcium citrate with calcium carbonate'. Together they form a unique fingerprint.

Cite this