Calcium carbonate and calcium glucoheptonate absorption compared in healthy adults
What it found
In 24 healthy adults, calcium from calcium glucoheptonate reached the blood at about 89% to 92% of the level seen with calcium carbonate.
Both forms were well tolerated after a single dose.
What they found
Studies in people
Calcium reaching the blood
Within 6 hours, calcium from calcium glucoheptonate reached 92% of the blood levels seen with calcium carbonate. Within 12 hours, it reached 89%.
Peak calcium levels
The highest blood calcium levels were slightly higher with calcium glucoheptonate than with calcium carbonate. These peaks appeared a bit sooner too.
Mild side effects
Five of the 24 people reported eight mild issues such as bloating, muscle pain, dizziness or headache. All went away within one day, and no serious problems occurred.
Other findings
Why calcium carbonate was used
Calcium carbonate is cheap, widely sold, and provides 40% elemental calcium by weight. It was chosen as the comparison product because it is commonly used in Southeast Asia.
What the authors conclude
- They found that calcium glucoheptonate delivered nearly as much calcium into the blood as calcium carbonate in healthy fasting adults.
- They note both products were well tolerated after a single dose.
- They suggest calcium glucoheptonate could be a useful supplement choice for people in Southeast Asia who need more calcium.
How it was done
Many people in Southeast Asia get very little calcium from food, so supplements are important. The authors wanted to see how well the body takes in calcium from a soluble salt called calcium glucoheptonate compared with calcium carbonate.
Twenty-four healthy Indonesian adults each took a single 500 mg dose of elemental calcium, once as calcium glucoheptonate and once as calcium carbonate, with a 7-day gap between doses. They fasted overnight before each dose, and researchers measured calcium levels in their blood for 12 hours.
What it can’t tell you
- This trial tested only a single dose, so it cannot show what happens when people take these supplements every day for months or years.
- The volunteers were healthy adults, so the results might differ in older women, teenagers, or people with bone conditions.
- Because the study was small, individual responses to either form of calcium may vary more than these averages suggest.
Who paid
- Conflicts
- This work was funded by Sanofi. Etienne Pouteau, Surajit Dutta, and Phuc HB Nguyen are current employees of Sanofi. The other authors declare no competing interests.
- Authors work at
- University of Indonesia, Indonesia; University of Medicine and Pharmacy, Vietnam
The paper
- Title
- Relative bioavailability and pharmacokinetic comparison of calcium glucoheptonate with calcium carbonate
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Wiria M, Tran HM, Nguyen PHB, Valencia O, Dutta S, Pouteau E (2020). Relative bioavailability and pharmacokinetic comparison of calcium glucoheptonate with calcium carbonate. Pharmacology research & perspectives. doi:10.1002/prp2.589Free full textPubMed 32302064DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error