Use of Compartmental Modeling and Datasets for Theoretical Lactating Women to Determine Conditions under Which Vitamin A-Specific Activity in Breast Milk Provides Accurate Estimates of Vitamin A Total Body Stores by Retinol Isotope Dilution.
J Nutr
; 152(7): 1629-1634, 2022 07 06.
Article
em En
| MEDLINE
| ID: mdl-35389495
ABSTRACT
BACKGROUND:
Vitamin A concentrations in breast milk are related to maternal vitamin A intake and status.OBJECTIVES:
Our objective was to identify conditions under which vitamin A specific activity in breast milk (SAm) could be used instead of retinol specific activity in plasma (SAp) to predict vitamin A total body stores (TBS) by retinol isotope dilution (RID).METHODS:
We used 12 previously-studied theoretical lactating women with assigned values for TBS (219-1348 µmol) and retinol kinetic parameters; we assumed subjects ingested a dose of stable isotope-labeled vitamin A. We expanded a 9-compartment steady state tracer model to include a parallel model for tracee (unlabeled retinol) and then adapted that model so vitamin A intake entered the system in 3 meals each day. Using compartmental analysis, we first simulated SAm and SAp after an overnight fast (as in actual RID experiments) and then with vitamin A intake also restricted in sequential meals on the day before sampling for RID.RESULTS:
After an overnight fast, SAm at day 21 postdosing was lower than SAp. However, if vitamin A intake was also restricted in 1, 2, or 3 meals before sampling, SAm/SAp (mean ± SD) was 0.92 ± 0.042, 0.96 ± 0.016, or 0.99 ± 0.004, respectively; results for days 14 and 28 were similar. When either SAp or SAm was used to predict TBS by RID on day 21 after 1-d restriction, predictions for all subjects were within 25% of assigned TBS.CONCLUSIONS:
Results indicate that, for theoretical lactating women with a wide range of vitamin A status, SAm will accurately predict TBS by RID at 2-4 wk postdosing if vitamin A intake is restricted for 1 d before sampling. If confirmed in community settings, results suggest that vitamin A status in lactating women can be determined without collecting blood.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Vitamina A
/
Deficiência de Vitamina A
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article