BACKGROUND: After a dose of labeled vitamin A is given to humans for estimating body stores of vitamin A, blood is customarily drawn at pseudo-equilibration times ranging from 11 to 26 d. OBJECTIVE: The objective was to determine whether a shorter sample collection interval (6 h or 3 d), which would be more realistic in field settings, can be used. DESIGN: Correlations of enrichment at 6 h or 3 d with enrichment at 21 d were made after an oral dose of deuterium-labeled vitamin A was given to Chinese schoolchildren (aged 10-11 y; n = 58) with marginal-to-normal vitamin A status. A predictive equation was then derived and applied to data obtained from a separate group of children to verify that the calculated enrichment at 21 d (determined by using data obtained at an earlier time point to predict 21-d enrichment) reflected directly measured enrichment at 21 d. RESULTS: Because 3-d isotope enrichment was found to correlate well with 21-d enrichment, a predictive equation was derived whereby 3-d data were used to predict isotope enrichment at pseudo-equilibration (ie, at 21 d). When the 3-d predictive equation was applied to a separate group of Chinese children, the calculated 21-d data (determined by using the 3-d data and the predictive equation) matched the directly measured 21-d data. Body stores of vitamin A determined from either the calculated or directly measured 21-d enrichment data also showed agreement. CONCLUSION: Percentage enrichment at 3 d (but not at 6 h) can be used to evaluate vitamin A body stores in humans.
BACKGROUND: After a dose of labeled vitamin A is given to humans for estimating body stores of vitamin A, blood is customarily drawn at pseudo-equilibration times ranging from 11 to 26 d. OBJECTIVE: The objective was to determine whether a shorter sample collection interval (6 h or 3 d), which would be more realistic in field settings, can be used. DESIGN: Correlations of enrichment at 6 h or 3 d with enrichment at 21 d were made after an oral dose of deuterium-labeled vitamin A was given to Chinese schoolchildren (aged 10-11 y; n = 58) with marginal-to-normal vitamin A status. A predictive equation was then derived and applied to data obtained from a separate group of children to verify that the calculated enrichment at 21 d (determined by using data obtained at an earlier time point to predict 21-d enrichment) reflected directly measured enrichment at 21 d. RESULTS: Because 3-d isotope enrichment was found to correlate well with 21-d enrichment, a predictive equation was derived whereby 3-d data were used to predict isotope enrichment at pseudo-equilibration (ie, at 21 d). When the 3-d predictive equation was applied to a separate group of Chinese children, the calculated 21-d data (determined by using the 3-d data and the predictive equation) matched the directly measured 21-d data. Body stores of vitamin A determined from either the calculated or directly measured 21-d enrichment data also showed agreement. CONCLUSION: Percentage enrichment at 3 d (but not at 6 h) can be used to evaluate vitamin A body stores in humans.
Authors: Bryan M Gannon; Ashley R Valentine; Christopher R Davis; Julie A Howe; Sherry A Tanumihardjo Journal: J Nutr Date: 2018-08-01 Impact factor: 4.798
Authors: Jean F Bationo; Augustin N Zeba; Nadine D Coulibaly; Jesse Sheftel; Christopher R Davis; Imael H N Bassole; Nicolas Barro; Jean B Ouedraogo; Sherry A Tanumihardjo Journal: Exp Biol Med (Maywood) Date: 2019-09-23
Authors: Sherry A Tanumihardjo; Robert M Russell; Charles B Stephensen; Bryan M Gannon; Neal E Craft; Marjorie J Haskell; Georg Lietz; Kerry Schulze; Daniel J Raiten Journal: J Nutr Date: 2016-08-10 Impact factor: 4.798