Retinol equivalency ratio of beta-carotene

Impact of Crude Palm Oil Fortified Cookies Supplementation on Anthropometry, Vitamin A and Hematological Status of School Children in India

Abstract. Objectives: Food-based strategies remain the most sustainable solutions for combating micronutrient deficiencies. Crude palm oil being the richest natural source of β-carotene, the study aimed to assess the impact of crude palm oil fortified cookies supplementation on anthropometry, vitamin A and hematological status of school children.

Methods: 444 children (boys-226, girls-218), aged 5-13 years from two Municipal Corporation of Delhi primary schools were enrolled. By draw of lot, children from one of the schools formed the experimental (n = 224; boys-119, girls-105) while other formed the placebo group (n = 220; boys-107; girls-113). Children from the experimental group received six crude palm oil fortified cookies providing 2152 μg of β-carotene while the placebo group received similar but non-fortified cookies each day for 50 school days. Anthropometry, vitamin A, and hematological status were assessed at baseline and post supplementation.

Results: Post supplementation, the number of stunted subjects reduced significantly (p < 0.05) in the experimental group. There was a significant increase in plasma retinol (170.9%; mean change: 1.55 ± 1.30 μmol/L - experimental group vs. 0.45 ± 0.99 μmol/L - placebo group) and β-carotene (p < 0.01; median change from 0.55 to 0.76 μmol/L - experimental group vs. 0.59 to 0.55 μmol/L -placebo group) concentrations of the experimental group. The increase in hematological parameters (mean change in Hemoglobin: 1.64 g/dL in experimental group vs. 2.10 g/dL in placebo group) of both the groups were however, comparable.

Conclusion: To address micronutrient deficiencies particularly in developing nations, the use of crude palm oil should be encouraged through supplementary feeding programs by way of ready-to-eat snacks.

Homology Models and Molecular Modeling of Human Retinoic Acid Metabolizing Enzymes Cytochrome P450 26A1 (CYP26A1) and P450 26B1 (CYP26B1)

Homology models of cytochrome P450 26A1 and cytochrome P450 26B1 were constructed using the crystal structures of human, CYP2C8, CYP2C9, and CYP3A4 as templates for the model building. The homology models generated were investigated for their docking capacities against the natural substrate all-trans-retinoic acid (atRA), five different tetralone-derived retinoic acid metabolizing blocking agents (RAMBAs), and R115866. Interaction energies (IE) and linear interaction energies (LIE) were calculated for all inhibitors in both homology models after molecular dynamics (MD) simulation of the enzyme-ligand complexes. The results revealed that the homologues had the capacity to distinguish between strong and weak inhibitors. Important residues in the active site were identified from the CYP26A1/B1-atRA complexes. Residues involved in hydrophobic interactions with atRA were Pro113, Phe222, Phe299, Val370, Pro371, and Phe374 in CYP26A1 and Leu88, Pro118, Phe222, Phe295, Ile368, and Tyr272 in CYP26B1. Hydrogen bonding interactions were observed between the atRA carboxylate group and Arg 90 in CYP26A1 and with Arg76, Arg95, and Ser369 in CYP26B1.

Stable isotope dilution techniques for assessing vitamin A status and bioefficacy of provitamin A carotenoids in humans

Vitamin A deficiency is a major global public health problem. Among the variety of techniques that are available for assessing human vitamin A status, evaluating the provitamin A nutritional values of foodstuffs and estimating human vitamin A requirements, isotope dilution provides the most accurate estimates. Although the relative expense of isotope dilution restricts its applications, it has an important function as the standard of reference for other techniques. Mathematical modelling plays an indispensable role in the interpretation of isotope dilution data. This review summarises recent applications of stable isotope methodology to determine human vitamin A status, estimate human vitamin A requirements, and calculate the bioconversion and bioefficacy of food carotenoids.