Calcium absorptive efficiency is positively related to body size.
BACKGROUND
Calcium absorption efficiency is a more important determinant of calcium balance than calcium intake itself. The sources of variability in absorptive performance are only partly elucidated.


OBJECTIVE
The aim of the study was to explore the relationship between body size and calcium absorption efficiency.


METHODS
Metabolic studies were performed on an inpatient metabolic unit in an academic health sciences center.


METHODS
One hundred seventy-eight women, with an average age of 50.2 yr, were studied from one to five times and yielded an aggregate data set containing 633 individual studies.


METHODS
Calcium absorption fraction was measured by the dual-tracer method. Observed values were expressed as residuals from predicted values for each woman's actual calcium intake, using the previously published relationship between intake and absorption.


RESULTS
Absorption residuals were significantly positively correlated with height, weight, and surface area, and after adjusting for estrogen status, these body size variables accounted for approximately 4% of the total variability.


CONCLUSIONS
The magnitude of the effect is such that a woman 1.8 m in height would absorb 30+% more calcium from a given intake than a woman 1.4 m tall.
Creighton University, 601 North 30th Street, Suite 4841, Omaha, Nebraska 68131, USA.
M Janet
MJ
Barger-Lux
Robert P
RP
Heaney
D000042:Absorption; D049628:Body Size; D001830:Body Surface Area; D001835:Body Weight; D002118:Calcium / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies
D002118:Calcium