Calcified Tissue International

, Volume 46, Issue 5, pp 300–304 | Cite as

Absorbability of calcium sources: The limited role of solubility

  • Robert P. Heaney
  • Robert R. Recker
  • Connie M. Weaver
Clinical Investigations


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 suggest 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.

Key words

Calcium absorption Solubility absorbability relationships Calcium salts Food calcium sources Biovailability 


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Copyright information

© Springer-Verlag New York Inc 1990

Authors and Affiliations

  • Robert P. Heaney
    • 2
  • Robert R. Recker
    • 2
  • Connie M. Weaver
    • 1
  1. 1.Department of Foods and NutritionPurdue UniversityWest LafayetteUSA
  2. 2.Center for Hard Tissue ResearchCreighton UniversityOmahaUSA

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