Calcium Bisglycinate is widely reported on the Internet. Every web site I have read makes the same claim: that thisform is BETTER ABSORBED than other forms of calcium.
When I researched this supplement for studies published 'peer reviewed' scientific or medical journals, I foundsome discrepancies between what is claimed on the web sites selling some form of Calcium Bisglycinate and what the published scientific papers say.
One web site selling a product with this form of calcium claims that it is almost twice as ABSORBABLE as other formsand they cite the following article as their source for the claim:
Heaney RP, Recher RR, Weaver CM. "Absorbability of calcium sources: the limited role of solubility," Calcif Tissue Int. 46:300-304, 1990.
When I checked the reference I found: (Note the italics given below are mine.)
Calcif Tissue Int. 1990 May;46(5):300-4."Absorbability of calcium sources: the limited role of solubility". Heaney RP, Recker RR, Weaver CM. Center for Hard Tissue Research, Creighton University, Omaha.
"Fractional absorption of seven chemically defined calcium sources was measured in normal adult women under standardized load conditions. Solubility of the sources in water at neutral pH ranged from a low of 0.04 mM to a high of 1500 mM. The relationship of solubility to absorbability was weak. In the range from 0.1 to 10 mM, within which most calcium supplement sources fall, there was no detectable effect of solubility on absorption. Data from four food sources are presented for comparison.
Absorbability of food calcium was not clearly related to absorbability of the dominant chemical form in the food concerned. These findings suggests that (1) even under controlled, chemically defined conditions, solubility of a source has very little influence on its absorbability; and (2) absorbability of calcium from food sources is determined mainly by other food components.
I am not sure how the web site author derived the claim that RP Heaney found that Calcium Bisglycinate was better absorbed that other forms of the mineral.... at least based on the article cited s the source of the claim.
Heany is a rather well known author of studies related to absorbability. As you will note from the listof studies below, all of which appeared in peer reviewed journals, he was the lead investigator in 3 of these studies.
The National Center for Biotechnological Information which is a resource supported by the National Library of Medicine and the National Institutes of Health in the United States lists the following published studies in their database that includes Heany as one of the authors. I include the full citations so that those who wish to read the studies can check out my conclusion that they do not seem to state that Calcium Bisgyclinate is better absorbed than other forms.
- Heaney RP, Dowell MS, Bierman J, Hale CA, Bendich A. "Absorbability and cost effectiveness in calcium supplementation" J Am Coll Nutr. 2001 Jun;20(3):239-46.
- Heaney RP, Dowell MS, Barger-Lux MJ. "Absorption of calcium as the carbonate and citrate salts, with some observations on method." Osteoporos Int. 1999;9(1):19-23.
- Heaney RP, Recker RR, Weaver CM. "Absorbability of calcium sources: the limited role of solubility."Calcif Tissue Int. 1990 May;46(5):300-4.
- Recker RR, Bammi A, Barger-Lux MJ, Heaney RP. "Calcium absorbability from milk products, an imitation milk, and calcium carbonate." Am J Clin Nutr. 1988 Jan;47(1):93-5.
I offer this review as a public service to those using this web site for their own information related to Osteoporosis and Osteopenia. I try to keep you informed about the peer reviewed research is saying. As for Calcium Bisglycinate you may well decide to purchase it... but not for the reason that some web sites claim.
If anyone finds different scientific references for the claim that Calcium Bisglycinate is better absorbed than other forms of calcium, I would be glad if you used the contact form on the About Us page to send me the reference so I may add to this section.
I want to provide the best information I am able.
Go here to read About supplements other than Calcium Bisglycinate