Relative bioavailability of zinc using weight gain of rats
Franz, K.B.; Kennedy, B.M.; Fellers, D.A.
Journal of Nutrition 110(11): 2263-2271
1980
ISSN/ISBN: 0022-3166 PMID: 7431126 Document Number: 167269
Weanling rats were fed on semipurified diets with different amounts of zinc to derive new measures of relative bioavailability of Zn (RBAZ). The different measures for RBAZ were slope-ratio methods of weight gain, total liver Zn and total femur Zn with 5 alternative measures developed from sigmoidal curves for weight gain estimated by a nonlinear, least-squares curve fitting computer programme. The slopes of weight gains explained a higher proportion of the true measure than similar slopes of femurs or livers as indicated by r2. The 95% confidence intervals of ratios were narrowest for weight gain methods. Of the 5 alternative methods 4 had RBAZ similar to the RBAZ of slope-ratio weight gain methods. These new methods provided a diversity of information and allowed more information to be obtained than from slope-ratio methods alone.