TY - JOUR
T1 - Kinetic analysis shows that vitamin A disposal rate in humans is positively correlated with vitamin A stores
AU - Cifelli, Christopher J.
AU - Green, Joanne B.
AU - Wang, Zhixu
AU - Yin, Shian
AU - Russell, Robert M.
AU - Tang, Guangwen
AU - Green, Michael H.
PY - 2008/5
Y1 - 2008/5
N2 - Vitamin A (VA) kinetics, storage, and disposal rate were determined in well-nourished Chinese and U.S. adults using model-based compartmental analysis. [2H8]Retinyl acetate (8.9 μmol) was orally administered to U.S. (n = 12; 59 ± 9 y; mean ± SD) and Chinese adults (n = 14; 54 ± 4 y) and serum tracer and VA concentrations were measured from 3 h to 56 d. Using the Windows version of the Simulation, Analysis and Modeling software, we determined that the average time from dosing until appearance of labeled retinol in serum was greater in U.S. subjects (40.6 ± 8.47 h) than in Chinese subjects (32.2 ± 5.84 h; P < 0.01). Model-predicted total traced mass (898 ± 637 vs. 237 ± 109 μmol), disposal rate (14.7 ± 5.87 vs. 5.58 ± 2.04 mmol/d), and system residence time (58.9 ± 28.7 vs. 42.9 ± 14.6 d) were greater in U.S. than in Chinese subjects (P < 0.05). The model-predicted VA mass and VA mass estimated by deuterated retinol dilution at 3 and 24 d did not differ. VA disposal rate was positively correlated with VA traced mass in Chinese (R2 = 0.556), U.S. (R2 = 0.579), and all subjects (R 2 = 0.808). Additionally, VA disposal rate was significantly correlated with serum retinol pool size (R2 = 0.227) and retinol concentration (R2 = 0.330) in all subjects. Our results support the hypothesis that VA stores are the principle determinant of VA disposal rate in healthy, well-nourished adults.
AB - Vitamin A (VA) kinetics, storage, and disposal rate were determined in well-nourished Chinese and U.S. adults using model-based compartmental analysis. [2H8]Retinyl acetate (8.9 μmol) was orally administered to U.S. (n = 12; 59 ± 9 y; mean ± SD) and Chinese adults (n = 14; 54 ± 4 y) and serum tracer and VA concentrations were measured from 3 h to 56 d. Using the Windows version of the Simulation, Analysis and Modeling software, we determined that the average time from dosing until appearance of labeled retinol in serum was greater in U.S. subjects (40.6 ± 8.47 h) than in Chinese subjects (32.2 ± 5.84 h; P < 0.01). Model-predicted total traced mass (898 ± 637 vs. 237 ± 109 μmol), disposal rate (14.7 ± 5.87 vs. 5.58 ± 2.04 mmol/d), and system residence time (58.9 ± 28.7 vs. 42.9 ± 14.6 d) were greater in U.S. than in Chinese subjects (P < 0.05). The model-predicted VA mass and VA mass estimated by deuterated retinol dilution at 3 and 24 d did not differ. VA disposal rate was positively correlated with VA traced mass in Chinese (R2 = 0.556), U.S. (R2 = 0.579), and all subjects (R 2 = 0.808). Additionally, VA disposal rate was significantly correlated with serum retinol pool size (R2 = 0.227) and retinol concentration (R2 = 0.330) in all subjects. Our results support the hypothesis that VA stores are the principle determinant of VA disposal rate in healthy, well-nourished adults.
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U2 - 10.1093/jn/138.5.971
DO - 10.1093/jn/138.5.971
M3 - Article
C2 - 18424609
AN - SCOPUS:42449084428
SN - 0022-3166
VL - 138
SP - 971
EP - 977
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 5
ER -