Related Experiment Videos
Assessment of vitamin A nutritional status in newborn preterm infants
Angela Regina Maciel Weinman1, Salim Moysés Jorge, Antonio Roberto Martins
1Department of Pediatrics, School of Medicine of Santa Maria, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
Insights
Assessing vitamin A status in preterm infants using serum retinol, retinol-binding protein (RBP), and transthyretin (TTR) is inadequate. The vitamin A relative dose-response test (RDR) remains the most reliable method for determining deficiency.
Area of Science:
- Biochemistry
- Pediatrics
- Nutritional Science
Background:
- Preterm infants are vulnerable to vitamin A deficiency.
- Accurate assessment of vitamin A status is crucial for optimal growth and development in neonates.
- Traditional serum markers may not reliably reflect vitamin A nutritional status in this population.
Purpose of the Study:
- To evaluate the efficacy of serum vitamin A, retinol-binding protein (RBP), and transthyretin (TTR) levels in assessing vitamin A nutritional status in preterm infants.
- To compare these serum markers against the vitamin A relative dose-response test (RDR) as the reference standard.
- To determine the diagnostic accuracy of various serum parameters and their ratios.
Main Methods:
- Serum retinol, RBP, and TTR levels, along with molar ratios, were measured in 120 infants at 7 days and 92 at 28 days.
- The vitamin A relative dose-response test (RDR) was employed as the gold standard for assessing vitamin A status.
- Receiver operator characteristic (ROC) curves were utilized to determine the sensitivity and specificity of serum markers.
Main Results:
- The RDR test indicated vitamin A deficiency in 60% of infants at 7 days and 51.1% at 28 days.
- Serum retinol at 28 days showed the highest accuracy (Area Under Curve = 0.710) but was only moderately accurate.
- No tested serum cutoff level demonstrated adequate sensitivity and specificity for assessing vitamin A status.
Conclusions:
- Serum levels of retinol, RBP, and TTR, as well as their molar ratios, are insufficient for accurately assessing vitamin A nutritional status in preterm infants.
- The vitamin A relative dose-response test (RDR) remains a more reliable method for this assessment.
- Further research may be needed to identify reliable biomarkers for vitamin A status in vulnerable infant populations.
Objective:
This study assessed the vitamin A nutritional status of preterm infants determined by the vitamin A relative dose-response test (RDR) compared with serum levels of vitamin A, retinol-binding protein (RBP), transthyretin (TTR), and retinol relations with carrier proteins.
Methods:
Serum levels of retinol, RBP, and TTR and retinol/RBP, retinol/TTR, and RBP/TTR molar ratios were determined in 120 infants at 7 d and in 92 at 28 d. For the determination of the performance of the tests, the RDR was considered the reference method. The sensitivity and specificity for all possible cutoff values were determined by constructing receiver operator characteristic curves. The areas under the curves were used to estimate the overall accuracy of the tests. The best cutoff values to be used for the calculation of sensitivity and specificity were determined with 95% confidence intervals.
Results:
RDR indicated vitamin A deficiency in 60% of the infants at 7 d and in 51.1% at 28 d. In the receiver operator characteristic curves, the best area under the curve was 0.710 obtained for serum retinol at 28 d of postnatal age and considered moderately accurate. The least inadequate cutoff level was set at 25 mg/dL, but no value was considered adequate due to low sensitivity and/or low specificity.
Conclusion:
Compared with RDR, the determination of serum levels of retinol, RBP, and TTR and their molar ratios are not adequate to assess nutritional vitamin A status in preterm infants.
Related Concept Videos
01:30Vitamins
01:23Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption
01:30Inflammatory Bowel Disease III: Diagnostic Studies and Management I-Nutritional Therapy
Diagnostic studies
A colonoscopy is the definitive screening test, distinguishing ulcerative colitis from other colon diseases with similar symptoms. During a colonoscopy test, inflamed mucosa with exudate ulcerations can be observed, and biopsies are taken to determine the histologic characteristics of the colonic...