Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 11/7/2006
Publication Date: 4/1/2007
Citation: Hunt, C., Johnson, L. 2007. Calcium requirement: new estimations for men and women by cross-sectional statistical analyses of metabolic calcium balance data [abstract]. Journal of Federation of American Societies for Experimental Biology. 21(5):A173-A174. Interpretive Summary:
Technical Abstract: To provide new estimates of the average Ca requirement for men and women, we determined the dietary Ca intake required to maintain neutral Ca balance. Ca balance data (Ca intake - [fecal Ca + urinary Ca]) were collected from 154 subjects (females: n=73, weight=77.1±18.5 kg, age=47.0±18.5 y [range: 20-75 y]; males: n=81, weight=76.6±12.6 kg, age=28.2±7.7 y [range: 19-64 y]) who participated in 19 different tightly-controlled feeding studies conducted in a metabolic unit. Balance data from the last 6-14 d of each dietary period (min. length 28 d) of each study (1-9 observations per subject) were analyzed. Data were excluded if individual intakes of Mg, Cu, Fe, P, or Zn fell below the Estimated Average Requirements or exceeded the 99th %tile of 1994 CSFII usual intakes (for Fe, above the UL). Daily intakes of Ca ranged between 415 and 1740 mg. The relation between intake and output was examined by fitting random coefficient models using SAS Proc Mixed. Coefficients were included to test for gender differences. The models predicted neutral Ca balance (defined as Ca output (Y) equal to Ca intake (C)) of 741 mg/d [507 – 1035, 95% prediction interval (PI); Y = 148.29 + 0.80C], 9.4 mg/kg/d [6.4 – 12.9, 95% PI; Y = 1.44 + 0.85C], or 0.28 mg/kcal/d [0.19 – 0.38, 95% PI; Y = 0.051 + 0.816]. Neither age nor sex affected the estimates when expressed as mg/d or mg/kg/d. The findings suggest a lower Ca requirement for men and women than estimated previously.