The modified relative-dose-response assay as an indicator of vitamin A status in a population of well-nourished American children

1990 ◽  
Vol 52 (6) ◽  
pp. 1064-1067 ◽  
Author(s):  
S A Tanumihardjo ◽  
P G Koellner ◽  
J A Olson
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
Vitamin A Status ◽  
American Children ◽  
Modified Relative Dose Response

Vitamin A status in preschool-age Indonesian children as assessed by the modified relative-dose-response assay

1990 ◽  
Vol 52 (6) ◽  
pp. 1068-1072 ◽  
Author(s):  
S A Tanumihardjo ◽  
Muhilal ◽  
Y Yuniar ◽  
D Permaesih ◽  
Z Sulaiman ◽  
...  
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
Preschool Age ◽  
Vitamin A Status ◽  
Modified Relative Dose Response

Vitamin A Status of Low-Income Pregnant Women in Iowa as Assessed by the Modified Relative Dose-Response

1993 ◽  
Vol 678 (1 Maternal Nutr) ◽  
pp. 344-345 ◽  
Author(s):  
P. K. DUITSMAN ◽  
S. A. TANUMIHARDJO ◽  
L. COOK ◽  
J. A. OLSON
Keyword(s):  
Vitamin A ◽  
Pregnant Women ◽  
Dose Response ◽  
Low Income ◽  
Vitamin A Status ◽  
Modified Relative Dose Response

scholarly journals Vitamin A intake and infection are associated with plasma retinol among pre-school children in rural Zambia

2012 ◽  
Vol 15 (9) ◽  
pp. 1688-1696 ◽  
Author(s):  
Christine Hotz ◽  
Justin Chileshe ◽  
Ward Siamusantu ◽  
Uma Palaniappan ◽  
Emmanuel Kafwembe
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
Acute Phase Proteins ◽  
Vitamin A Deficiency ◽  
Dietary Vitamin ◽  
Response Test ◽  
Post Harvest ◽  
Vitamin A Status ◽  
Plasma Retinol ◽  
Modified Relative Dose Response

AbstractObjectiveTo determine the prevalence of vitamin A deficiency, infection and adequacy of vitamin A intakes among Zambian children, and the contribution of dietary vitamin A and infection to vitamin A status.DesignA cross-sectional survey of vitamin A intakes by the 24 h recall method, vitamin A status by plasma retinol and the modified relative dose-response test, and infection by acute-phase proteins.SettingRural communities in Central and Eastern Provinces of Zambia.SubjectsChildren 2–5 years of age.ResultsThe prevalence of vitamin A deficiency was 56 % by plasma retinol, 48 % with infection-adjusted plasma retinol and 22 % by the modified relative dose-response test. The majority of children (61 %) had a current infection. Vitamin A intakes were relatively high (331 to 585 μg retinol activity equivalents/d in the harvest/early post-harvest and late post-harvest seasons, respectively) and the prevalence of inadequate intakes was <1 % when compared with the Estimated Average Requirement (210 and 275 μg retinol activity equivalents/d for children aged 1–3 and 4–8 years, respectively). Elevated α-1-acid glycoprotein was negatively associated with plasma retinol (P< 0·0 0 1) and vitamin A intake was positively associated with plasma retinol (P< 0·05), but only when estimated assuming a 26:1 retinol equivalence for provitamin A from green and yellow vegetables.ConclusionsInfection and vitamin A intakes were significant determinants of plasma retinol. We cannot conclude which indicator more accurately represents the true vitamin A status of the population. Reasons for the persistent high prevalence of vitamin A deficiency in the presence of adequate vitamin A intakes are unclear, but the high rates of infection may play a role.

Retinol-binding protein, retinol, and modified-relative-dose response in Ugandan children aged 12–23 months and their non-pregnant caregivers

2021 ◽  
pp. 153537022098547
Author(s):  
Ralph D Whitehead ◽  
Nicole D Ford ◽  
Carine Mapango ◽  
Laird J Ruth ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
High Performance ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vitamin A Status ◽  
Plasma Retinol ◽  
Commercial Enzyme Immunoassay ◽  
Modified Relative Dose Response

Retinol-binding protein (RBP), retinol, and modified-relative-dose response (MRDR) are used to assess vitamin A status. We describe vitamin A status in Ugandan children and women using dried blood spot (DBS) RBP, serum RBP, plasma retinol, and MRDR and compare DBS-RBP, serum RBP, and plasma retinol. Blood was collected from 39 children aged 12–23 months and 28 non-pregnant mothers aged 15–49 years as a subsample from a survey in Amuria district, Uganda, in 2016. DBS RBP was assessed using a commercial enzyme immunoassay kit, serum RBP using an in-house sandwich enzyme-linked immunosorbent assay, and plasma retinol/MRDR test using high-performance liquid chromatography. We examined (a) median concentration or value (Q1, Q3); (b) R2 between DBS-RBP, serum RBP, and plasma retinol; and (c) Bland-Altman plots. Median (Q1, Q3) for children and mothers, respectively, were as follows: DBS-RBP 1.15 µmol/L (0.97, 1.42) and 1.73 (1.52, 1.96), serum RBP 0.95 µmol/L (0.78, 1.18) and 1.47 µmol/L (1.30, 1.79), plasma retinol 0.82 µmol/L (0.67, 0.99) and 1.33 µmol/L (1.22, 1.58), and MRDR 0.025 (0.014, 0.042) and 0.014 (0.009, 0.019). DBS RBP-serum RBP R2 was 0.09 for both children and mothers. The mean biases were −0.19 µmol/L (95% limits of agreement [LOA] 0.62, −0.99) for children and −0.01 µmol/L (95% LOA −1.11, −1.31) for mothers. DBS RBP-plasma retinol R2 was 0.11 for children and 0.13 for mothers. Mean biases were 0.33 µmol/L (95% LOA −0.37, 1.03) for children, and 0.29 µmol/L (95% LOA −0.69, 1.27) for mothers. Serum RBP-plasma retinol R2 was 0.75 for children and 0.55 for mothers, with mean biases of 0.13 µmol/L (95% LOA −0.23, 0.49) for children and 0.18 µmol/L (95% LOA −0.61, 0.96) for mothers. Results varied by indicator and matrix. The serum RBP-retinol R2 for children was moderate (0.75), but poor for other comparisons. Understanding the relationships among vitamin A indicators across contexts and population groups is needed.

Assessment of the vitamin A status in lactating and nonlactating, nonpregnant Indonesian women by use of the modified-relative-dose-response (MRDR) test

1994 ◽  
Vol 60 (1) ◽  
pp. 142-147 ◽  
Author(s):  
S A Tanumihardjo ◽  
Muherdiyantiningsih ◽  
D Permaesih ◽  
A M Dahro ◽  
Muhilal ◽  
...  
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
Vitamin A Status ◽  
Modified Relative Dose Response

The Vitamin A Status of Zambian Children in a Community of Vitamin A Supplementation and Sugar Fortification Strategies as measured by the Modified Relative Dose Response (MRDR) Test

2009 ◽  
Vol 79 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Emmanuel M. Kafwembe ◽  
James Chipipa ◽  
Eric Njunju ◽  
Roma Chilengi
Keyword(s):  
Vitamin A ◽  
Dose Response ◽  
Vitamin A Deficiency ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Vitamin A Supplementation ◽  
Vitamin A Status ◽  
The Status ◽  
Modified Relative Dose Response

The main objective of the study was to determine the vitamin A status of Zambian children less than five years of age in a community where strategies of vitamin A supplementation and consumption of vitamin A fortified sugar have been introduced. In a cross-sectional study, a total of 537 children were enrolled. Their vitamin A status was measured using the modified relative dose response (MRDR) test. Their vitamin A status was compared to the status measured using a similar method in 1996, before vitamin A supplementation through capsule distribution and fortification of sugar was implemented as strategies to reduce vitamin A deficiency in the country. Results showed that the vitamin A status of children improved markedly as a result of these strategies.

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