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Turck D, Bohn T, Castenmiller J, de Henauw S, Hirsch‐Ernst K, Knutsen HK, Maciuk A, Mangelsdorf I, McArdle HJ, Pentieva K, Siani A, Thies F, Tsabouri S, Vinceti M, Lietz G, Passeri G, Craciun I, Fabiani L, Horvath Z, Valtueña Martínez S, Naska A. Scientific opinion on the tolerable upper intake level for preformed vitamin A and β-carotene. EFSA J 2024; 22:e8814. [PMID: 38846679 PMCID: PMC11154838 DOI: 10.2903/j.efsa.2024.8814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2024] Open
Abstract
Following two requests from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for preformed vitamin A and β-carotene. Systematic reviews of the literature were conducted for priority adverse health effects of excess vitamin A intake, namely teratogenicity, hepatotoxicity and endpoints related to bone health. Available data did not allow to address whether β-carotene could potentiate preformed vitamin A toxicity. Teratogenicity was selected as the critical effect on which to base the UL for preformed vitamin A. The Panel proposes to retain the UL for preformed vitamin A of 3000 μg RE/day for adults. This UL applies to men and women, including women of child-bearing age, pregnant and lactating women and post-menopausal women. This value was scaled down to other population groups using allometric scaling (body weight0.75), leading to ULs between 600 μg RE/day (infants 4-11 months) and 2600 μg RE/day (adolescents 15-17 years). Based on available intake data, European populations are unlikely to exceed the UL for preformed vitamin A if consumption of liver, offal and products thereof is limited to once per month or less. Women who are planning to become pregnant or who are pregnant are advised not to consume liver products. Lung cancer risk was selected as the critical effect of excess supplemental β-carotene. The available data were not sufficient and suitable to characterise a dose-response relationship and identify a reference point; therefore, no UL could be established. There is no indication that β-carotene intake from the background diet is associated with adverse health effects. Smokers should avoid consuming food supplements containing β-carotene. The use of supplemental β-carotene by the general population should be limited to the purpose of meeting vitamin A requirements.
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Chuang JC, Clifford AJ, Kim SH, Novotny JA, Kelly PB, Holstege DM, Walzem RL. Separation of Lipoproteins for Quantitative Analysis of 14C-Labeled Lipid-Soluble Compounds by Accelerator Mass Spectrometry. Int J Mol Sci 2024; 25:1856. [PMID: 38339135 PMCID: PMC10855872 DOI: 10.3390/ijms25031856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
To date, 14C tracer studies using accelerator mass spectrometry (AMS) have not yet resolved lipid-soluble analytes into individual lipoprotein density subclasses. The objective of this work was to develop a reliable method for lipoprotein separation and quantitative recovery for biokinetic modeling purposes. The novel method developed provides the means for use of small volumes (10-200 µL) of frozen plasma as a starting material for continuous isopycnic lipoprotein separation within a carbon- and pH-stable analyte matrix, which, following post-separation fraction clean up, created samples suitable for highly accurate 14C/12C isotope ratio determinations by AMS. Manual aspiration achieved 99.2 ± 0.41% recovery of [5-14CH3]-(2R, 4'R, 8'R)-α-tocopherol contained within 25 µL plasma recovered in triacylglycerol rich lipoproteins (TRL = Chylomicrons + VLDL), LDL, HDL, and infranatant (INF) from each of 10 different sampling times for one male and one female subject, n = 20 total samples. Small sample volumes of previously frozen plasma and high analyte recoveries make this an attractive method for AMS studies using newer, smaller footprint AMS equipment to develop genuine tracer analyses of lipophilic nutrients or compounds in all human age ranges.
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Affiliation(s)
| | | | - Seung-Hyun Kim
- Department of Applied Bioscience, College of Life and Environmental Science, Konkuk University, Seoul 143-701, Republic of Korea;
| | - Janet A. Novotny
- U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, 10300 Baltimore Avenue, Beltsville, MD 20705, USA;
| | - Peter B. Kelly
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Dirk M. Holstege
- UC Davis Analytical Lab, University of California, Davis, CA 95616, USA
| | - Rosemary L. Walzem
- Poultry Science Department, Graduate Faculty of Nutrition, Texas A&M University, College Station, TX 77843, USA
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Suri DJ, Sombié OO, Zeba AN, Nama GM, Bekele TH, Woldeyohannes M, van Stuijvenberg ME, Dhansay MA, Urio EM, Loechl CU, Gannon BM, Davis CR, Grahn M, Suchdev PS, Tanumihardjo SA. Association between Biomarkers of Inflammation and Total Liver Vitamin A Reserves Estimated by 13C-Retinol Isotope Dilution among Preschool Children in 5 African Countries. J Nutr 2023; 153:622-635. [PMID: 36931745 DOI: 10.1016/j.tjnut.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/11/2022] [Accepted: 10/28/2022] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Vitamin A (VA) assessment is important for targeting public health programs. Retinol isotope dilution (RID) is a sensitive method to estimate total body VA stores (TBSs) and total liver reserves (TLRs), but the impact of subclinical inflammation on RID is unclear. OBJECTIVE We determined the association between TBSs and TLRs, estimated by RID, and inflammation among preschool children without clinical infection in Burkina Faso, Cameroon, Ethiopia, South Africa, and Tanzania. METHODS Five studies (n = 532; 47.9 ± 8.3 mo; 49.0% male) included 13C-RID and measurement of inflammation markers, CRP, and α1-acid glycoprotein (AGP). Spearman correlations were used to evaluate TBSs and TLRs with inflammation biomarkers. Wilcoxon and Kruskal-Wallis tests were used to compare TBSs and TLRs by inflammation categories [normal vs. elevated CRP (>5 mg/L) or AGP (>1 g/L)] and inflammation stage [reference, incubation (elevated CRP), early convalescence (elevated CRP and AGP), and late convalescence (elevated AGP)]. RESULTS Complete data were available for 439 children. Median (Q1, Q3) TLRs ranged from 0.12 (0.07, 0.18) μmol/g in Ethiopia to 1.10 (0.88, 1.38) μmol/g in South Africa. Elevated CRP ranged from 4% in Burkina Faso to 42% in Cameroon, and elevated AGP from 20% in Tanzania to 58% in Cameroon. Pooled analysis (excluding Cameroon) showed a negative correlation between TBSs and AGP (ρ = -0.131, P = 0.01). Children with elevated AGP had higher probability of having lower TBSs (probability = 0.61, P = 0.002). TBSs differed among infection stages (P = 0.020). Correlations between TLRs and CRP or AGP were not significant. CONCLUSIONS No indication of systematic bias in RID-estimated TLRs was found due to subclinical inflammation among preschool children. The inverse relationship between TBSs and AGP may reflect decreased stores after infection or an effect of inflammation on isotope partitioning. Further research should investigate potential confounding variables to improve TBS-estimate validity.
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Affiliation(s)
- Devika J Suri
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA.
| | - Olivier O Sombié
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Augustin N Zeba
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | | | | | | | - Martha E van Stuijvenberg
- Non-Communicable Diseases Research Unit, South African Medical Research Council, South Africa; Division of Human Nutrition, Stellenbosch University, South Africa
| | - Muhammad A Dhansay
- Division of Human Nutrition, Stellenbosch University, South Africa; Burden of Disease Research Unit, South African Medical Research Council, South Africa; Department of Paediatrics and Child Health, Stellenbosch University, South Africa
| | | | - Cornelia U Loechl
- Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Bryan M Gannon
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Christopher R Davis
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael Grahn
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Sherry A Tanumihardjo
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA.
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Baliu-Rodriguez D, Stewart BJ, Ognibene TJ. HPLC-Parallel accelerator and molecular mass spectrometry analysis of 14C-labeled amino acids. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1216:123590. [PMID: 36669256 PMCID: PMC9994536 DOI: 10.1016/j.jchromb.2022.123590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/31/2022] [Indexed: 01/06/2023]
Abstract
Accelerator mass spectrometry (AMS) is the method of choice for quantitation of low amounts of 14C-labeled biomolecules. Despite exquisite sensitivity, an important limitation of AMS is its inability to provide structural information about the analyte. This limitation is not critical when the labeled compounds are well-characterized prior to AMS analysis. However, analyte identity is important in other experiments where, for example, a compound is metabolized and the structures of its metabolites are not known. We previously described a moving wire interface that enables direct AMS measurement of liquid sample in the form of discrete drops or HPLC eluent without the need for individual fraction collection, termed liquid sample-AMS (LS-AMS). We now report the coupling of LS-AMS with a molecular mass spectrometer, providing parallel accelerator and molecular mass spectrometry (PAMMS) detection of analytes separated by liquid chromatography. The repeatability of the method was examined by performing repeated injections of 14C-labeled tryptophan, and relative standard deviations of the 14C peak areas were ≤10.57% after applying a normalization factor based on a standard. Five 14C-labeled amino acids were separated and detected to provide simultaneous quantitative AMS and structural MS data, and AMS results were compared with solid sample-AMS (SS-AMS) data using Bland-Altman plots. To demonstrate the utility of the workflow, yeast cells were grown in a medium with 14C-labeled tryptophan. The cell extracts were analyzed by PAMMS, and 14C was detected in tryptophan and its metabolite kynurenine.
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Affiliation(s)
- David Baliu-Rodriguez
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA.
| | - Benjamin J Stewart
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
| | - Ted J Ognibene
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
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Significantly Reduced Retinol Binding Protein 4 (RBP4) Levels in Critically Ill COVID-19 Patients. Nutrients 2022; 14:nu14102007. [PMID: 35631143 PMCID: PMC9147114 DOI: 10.3390/nu14102007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/05/2022] [Accepted: 05/08/2022] [Indexed: 12/13/2022] Open
Abstract
The SARS-CoV-2 virus is the causative agent of the COVID-19 pandemic. The disease causes respiratory failure in some individuals accompanied by marked hyperinflammation. Vitamin A (syn. retinol) can exist in the body in the storage form as retinyl ester, or in the transcriptionally active form as retinoic acid. The main function of retinol binding protein 4 (RBP4), synthesized in the liver, is to transport hydrophobic vitamin A to various tissues. Vitamin A has an important role in the innate and acquired immune system. In particular, it is involved in the repair of lung tissue after infections. In viral respiratory diseases such as influenza pneumonia, vitamin A supplementation has been shown to reduce mortality in animal models. In critically ill COVID-19 patients, a significant decrease in plasma vitamin A levels and an association with increased mortality have been observed. However, there is no evidence on RBP4 in relation to COVID-19. This prospective, multicenter, observational, cross-sectional study examined RBP4 (enzyme-linked immunosorbent assay) and vitamin A plasma levels (high-performance liquid chromatography) in COVID-19 patients, including 59 hospitalized patients. Of these, 19 developed critical illness (ARDS/ECMO), 20 developed severe illness (oxygenation disorder), and 20 developed moderate illness (no oxygenation disorder). Twenty age-matched convalescent patients following SARS-CoV-2 infection, were used as a control group. Reduced RBP4 plasma levels significantly correlated with impaired liver function and elevated inflammatory markers (CRP, lymphocytopenia). RBP4 levels were decreased in hospitalized patients with critical illness compared to nonpatients (p < 0.01). In comparison, significantly lower vitamin A levels were detected in hospitalized patients regardless of disease severity. Overall, we conclude that RBP4 plasma levels are significantly reduced in critically ill COVID-19 patients during acute inflammation, and vitamin A levels are significantly reduced in patients with moderate/severe/critical illness during the acute phase of illness.
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Yu L, Wang Y, Yu D, Zhang S, Zheng F, Ding N, Zhu L, Zhu Q, Sun W, Li S, Zhang G, Chen L, Liu Y, Yang L, Feng J. Association between Serum Vitamin A, Blood Lipid Level and Dyslipidemia among Chinese Children and Adolescents. Nutrients 2022; 14:nu14071444. [PMID: 35406055 PMCID: PMC9002720 DOI: 10.3390/nu14071444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/20/2022] [Accepted: 03/28/2022] [Indexed: 01/11/2023] Open
Abstract
Background: To study the relationship between serum vitamin A (VA) level and blood lipid profiles in children and adolescents aged 6−18 years, as well as the effect of VA on dyslipidemia. Methods: The project adopted a multistage stratified cluster sampling method. The Food Frequency Questionnaire (FFQ) was used to obtain dietary factors data. Blood samples of subjects were taken via venipuncture. Generalized linear models were used to explore the correlation be-tween VA and biochemical indicators, as well as stratified and inter-actions analysis to explore the influence of confounders on these relationships. Generalized linear models were constructed to explore the association between VA and blood lipids. Restricted cubic splines were used to characterize dose−response associations between serum VA and dyslipidemia based on logistic regression. Results: Serum VA was positively correlated with TC, TG and HDL-C (p < 0.05), but these associations were influenced by age (p < 0.05). The adjusted odds ratio (OR) values of VA for hypercho lesterolemia, hypertriglyceridemia, mixed hyperlipidemia and low high-density lipoprotein cholesterolemia were 3.283, 3.239, 5.219 and 0.346, respectively (p < 0.01). Meanwhile, significant age interactions affected the relationship between VA and TC, as well as TG and LDL-C (p < 0.01). Conclusion: Serum VA was positively correlated with blood lipids, but these associations were influenced by age. VA was a risk factor for dyslipidemias, such as hypercholesterolemia, hypertriglyceridemia and mixed hyperlipidemia, but was a protective factor for low high-density lipoprotein cholesterolemia.
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Affiliation(s)
- Lianlong Yu
- Shandong Center for Disease Control and Prevention, Jinan 250014, China; (L.Y.); (F.Z.); (W.S.); (S.L.); (G.Z.); (L.C.)
| | - Yongjun Wang
- Department of Clinical Nutrition, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan 250014, China;
| | - Dongmei Yu
- National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing 100050, China;
| | - Shixiu Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan 250012, China;
| | - Fengjia Zheng
- Shandong Center for Disease Control and Prevention, Jinan 250014, China; (L.Y.); (F.Z.); (W.S.); (S.L.); (G.Z.); (L.C.)
| | - Ning Ding
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, China;
| | - Lichao Zhu
- Department of Pediatric Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, China;
| | - Qianrang Zhu
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China;
| | - Wenkui Sun
- Shandong Center for Disease Control and Prevention, Jinan 250014, China; (L.Y.); (F.Z.); (W.S.); (S.L.); (G.Z.); (L.C.)
| | - Suyun Li
- Shandong Center for Disease Control and Prevention, Jinan 250014, China; (L.Y.); (F.Z.); (W.S.); (S.L.); (G.Z.); (L.C.)
| | - Gaohui Zhang
- Shandong Center for Disease Control and Prevention, Jinan 250014, China; (L.Y.); (F.Z.); (W.S.); (S.L.); (G.Z.); (L.C.)
| | - Liangxia Chen
- Shandong Center for Disease Control and Prevention, Jinan 250014, China; (L.Y.); (F.Z.); (W.S.); (S.L.); (G.Z.); (L.C.)
| | - Yiya Liu
- Guizhou Center for Disease Control and Prevention, Guiyang 550001, China;
| | - Li Yang
- Jinan Center for Disease Control and Prevention, Jinan 250021, China
- Correspondence: (L.Y.); (J.F.); Tel.: +86-18615422180 (L.Y.); +86-0531-82166927 (J.F.)
| | - Jian Feng
- Department of Clinical Nutrition, Qilu Hospital of Shandong University, Jinan 250012, China
- Correspondence: (L.Y.); (J.F.); Tel.: +86-18615422180 (L.Y.); +86-0531-82166927 (J.F.)
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Bahlool AZ, Grant C, Cryan SA, Keane J, O'Sullivan MP. All trans retinoic acid as a host-directed immunotherapy for tuberculosis. CURRENT RESEARCH IN IMMUNOLOGY 2022; 3:54-72. [PMID: 35496824 PMCID: PMC9040133 DOI: 10.1016/j.crimmu.2022.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/11/2022] [Accepted: 03/22/2022] [Indexed: 12/22/2022] Open
Abstract
Tuberculosis (TB) is the top bacterial infectious disease killer and one of the top ten causes of death worldwide. The emergence of strains of multiple drug-resistant tuberculosis (MDR-TB) has pushed our available stock of anti-TB agents to the limit of effectiveness. This has increased the urgent need to develop novel treatment strategies using currently available resources. An adjunctive, host-directed therapy (HDT) designed to act on the host, instead of the bacteria, by boosting the host immune response through activation of intracellular pathways could be the answer. The integration of multidisciplinary approaches of repurposing currently FDA-approved drugs, with a targeted drug-delivery platform is a very promising option to reduce the long timeline associated with the approval of new drugs - time that cannot be afforded given the current levels of morbidity and mortality associated with TB infection. The deficiency of vitamin A has been reported to be highly associated with the increased susceptibility of TB. All trans retinoic acid (ATRA), the active metabolite of vitamin A, has proven to be very efficacious against TB both in vitro and in vivo. In this review, we discuss and summarise the importance of vitamin A metabolites in the fight against TB and what is known regarding the molecular mechanisms of ATRA as a host-directed therapy for TB including its effect on macrophages cytokine profile and cellular pathways. Furthermore, we focus on the issues behind why previous clinical trials with vitamin A supplementation have failed, and how these issues might be overcome. Tuberculosis deaths and resistance are increasing – novel therapies are needed. Vitamin A deficiency is a strong risk factor for active tuberculosis in contacts. All Trans Retinoic Acid is a promising host-directed therapy for tuberculosis. It has pleiotropic effects on macrophages & other immune cells in vitro and in vivo. Inhaled rather than systemic All Trans Retinoic Acid therapy may be most effective.
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Affiliation(s)
- Ahmad Z. Bahlool
- School of Pharmacy and Biomolecular Sciences (PBS), Royal College of Surgeons in Ireland (RCSI), 123 St Stephens Green, Dublin 2, Ireland
- Tissue Engineering Research Group (TERG), Royal College of Surgeons in Ireland (RCSI), 123 St Stephens Green, Dublin 2, Ireland
- Department of Clinical Medicine, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, The University of Dublin, Dublin 8, Ireland
| | - Conor Grant
- Department of Clinical Medicine, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, The University of Dublin, Dublin 8, Ireland
| | - Sally-Ann Cryan
- School of Pharmacy and Biomolecular Sciences (PBS), Royal College of Surgeons in Ireland (RCSI), 123 St Stephens Green, Dublin 2, Ireland
- Tissue Engineering Research Group (TERG), Royal College of Surgeons in Ireland (RCSI), 123 St Stephens Green, Dublin 2, Ireland
- SFI Advanced Materials and Bioengineering Research (AMBER) Centre, RCSI & TCD, Dublin, Ireland
- SFI Centre for Research in Medical Devices (CURAM), RCSI, Dublin and National University of Ireland, Galway, Ireland
| | - Joseph Keane
- Department of Clinical Medicine, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, The University of Dublin, Dublin 8, Ireland
| | - Mary P. O'Sullivan
- Department of Clinical Medicine, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, The University of Dublin, Dublin 8, Ireland
- Corresponding author.
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8
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Stephensen CB, Lietz G. Vitamin A in resistance to and recovery from infection: relevance to SARS-CoV2. Br J Nutr 2021; 126:1663-1672. [PMID: 33468263 PMCID: PMC7884725 DOI: 10.1017/s0007114521000246] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 12/30/2020] [Accepted: 01/13/2021] [Indexed: 12/16/2022]
Abstract
SARS-CoV2 infects respiratory epithelial cells via its cellular receptor angiotensin-converting enzyme 2, causing a viral pneumonia with pronounced inflammation resulting in significant damage to the lungs and other organ systems, including the kidneys, though symptoms and disease severity are quite variable depending on the intensity of exposure and presence of underlying conditions that may affect the immune response. The resulting disease, coronavirus disease 2019 (COVID-19), can cause multi-organ system dysfunction in patients requiring hospitalisation and intensive care treatment. Serious infections like COVID-19 often negatively affect nutritional status, and the resulting nutritional deficiencies may increase disease severity and impair recovery. One example is the viral infection measles, where associated vitamin A (VA) deficiency increases disease severity and appropriately timed supplementation during recovery reduces mortality and hastens recovery. VA may play a similar role in COVID-19. First, VA is important in maintaining innate and adaptive immunity to promote clearance of a primary infection as well as minimise risks from secondary infections. Second, VA plays a unique role in the respiratory tract, minimising damaging inflammation, supporting repair of respiratory epithelium and preventing fibrosis. Third, VA deficiency may develop during COVID-19 due to specific effects on lung and liver stores caused by inflammation and impaired kidney function, suggesting that supplements may be needed to restore adequate status. Fourth, VA supplementation may counteract adverse effects of SARS-CoV2 on the angiotensin system as well as minimises adverse effects of some COVID-19 therapies. Evaluating interactions of SARS-CoV2 infection with VA metabolism may thus provide improved COVID-19 therapy.
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Affiliation(s)
- C. B. Stephensen
- Immunity and Disease Prevention Research Unit, USDA Western Human Nutrition Research Center, and Nutrition Department, University of California, Davis, CA, USA
| | - G. Lietz
- Human Nutrition Research Centre, Population Health Sciences Institute, Newcastle University, Newcastle upon TyneNE2 4HH, UK
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Tepasse PR, Vollenberg R, Fobker M, Kabar I, Schmidt H, Meier JA, Nowacki T, Hüsing-Kabar A. Vitamin A Plasma Levels in COVID-19 Patients: A Prospective Multicenter Study and Hypothesis. Nutrients 2021; 13:nu13072173. [PMID: 34202697 PMCID: PMC8308355 DOI: 10.3390/nu13072173] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/17/2021] [Accepted: 06/20/2021] [Indexed: 12/15/2022] Open
Abstract
COVID-19 is a pandemic disease that causes severe pulmonary damage and hyperinflammation. Vitamin A is a crucial factor in the development of immune functions and is known to be reduced in cases of acute inflammation. This prospective, multicenter observational cross-sectional study analyzed vitamin A plasma levels in SARS-CoV-2 infected individuals, and 40 hospitalized patients were included. Of these, 22 developed critical disease (Acute Respiratory Distress Syndrome [ARDS]/Extracorporeal membrane oxygenation [ECMO]), 9 developed severe disease (oxygen supplementation), and 9 developed moderate disease (no oxygen supplementation). A total of 47 age-matched convalescent persons that had been earlier infected with SARS-CoV-2 were included as the control group. Vitamin A plasma levels were determined by high-performance liquid chromatography. Reduced vitamin A plasma levels correlated significantly with increased levels of inflammatory markers (CRP, ferritin) and with markers of acute SARS-CoV-2 infection (reduced lymphocyte count, LDH). Vitamin A levels were significantly lower in hospitalized patients than in convalescent persons (p < 0.01). Of the hospitalized patients, those who were critically ill showed significantly lower vitamin A levels than those who were moderately ill (p < 0.05). Vitamin A plasma levels below 0.2 mg/L were significantly associated with the development of ARDS (OR = 5.54 [1.01–30.26]; p = 0.048) and mortality (OR 5.21 [1.06–25.5], p = 0.042). Taken together, we conclude that vitamin A plasma levels in COVID-19 patients are reduced during acute inflammation and that severely reduced plasma levels of vitamin A are significantly associated with ARDS and mortality.
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Affiliation(s)
- Phil-Robin Tepasse
- Department of Medicine B for Gastroenterology, Hepatology, Endocrinology and Clinical Infectiology, University Hospital Muenster, 48149 Muenster, Germany; (R.V.); (I.K.); (H.S.); (J.A.M.); (T.N.); (A.H.-K.)
- Correspondence: ; Tel.: +49-251-834-4882
| | - Richard Vollenberg
- Department of Medicine B for Gastroenterology, Hepatology, Endocrinology and Clinical Infectiology, University Hospital Muenster, 48149 Muenster, Germany; (R.V.); (I.K.); (H.S.); (J.A.M.); (T.N.); (A.H.-K.)
| | - Manfred Fobker
- Center for Laboratory Medicine, University Hospital Muenster, 48149 Muenster, Germany;
| | - Iyad Kabar
- Department of Medicine B for Gastroenterology, Hepatology, Endocrinology and Clinical Infectiology, University Hospital Muenster, 48149 Muenster, Germany; (R.V.); (I.K.); (H.S.); (J.A.M.); (T.N.); (A.H.-K.)
| | - Hartmut Schmidt
- Department of Medicine B for Gastroenterology, Hepatology, Endocrinology and Clinical Infectiology, University Hospital Muenster, 48149 Muenster, Germany; (R.V.); (I.K.); (H.S.); (J.A.M.); (T.N.); (A.H.-K.)
| | - Jörn Arne Meier
- Department of Medicine B for Gastroenterology, Hepatology, Endocrinology and Clinical Infectiology, University Hospital Muenster, 48149 Muenster, Germany; (R.V.); (I.K.); (H.S.); (J.A.M.); (T.N.); (A.H.-K.)
| | - Tobias Nowacki
- Department of Medicine B for Gastroenterology, Hepatology, Endocrinology and Clinical Infectiology, University Hospital Muenster, 48149 Muenster, Germany; (R.V.); (I.K.); (H.S.); (J.A.M.); (T.N.); (A.H.-K.)
| | - Anna Hüsing-Kabar
- Department of Medicine B for Gastroenterology, Hepatology, Endocrinology and Clinical Infectiology, University Hospital Muenster, 48149 Muenster, Germany; (R.V.); (I.K.); (H.S.); (J.A.M.); (T.N.); (A.H.-K.)
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Palmer AC, Jobarteh ML, Chipili M, Greene MD, Oxley A, Lietz G, Mwanza R, Haskell MJ. Biofortified and fortified maize consumption reduces prevalence of low milk retinol, but does not increase vitamin A stores of breastfeeding Zambian infants with adequate reserves: a randomized controlled trial. Am J Clin Nutr 2021; 113:1209-1220. [PMID: 33693468 DOI: 10.1093/ajcn/nqaa429] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 12/16/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Replacement of conventional staples with biofortified or industrially fortified staples in household diets may increase maternal breast milk retinol content and vitamin A intakes from complementary foods, improving infant total body stores (TBS) of vitamin A. OBJECTIVES To determine whether biofortified or industrially fortified maize consumption by Zambian women and their breastfeeding infants could improve milk retinol concentration and infant TBS. METHODS We randomly assigned 255 lactating women and their 9-mo-old infants to a 90-d intervention providing 0 µg retinol equivalents (RE)/d as conventional maize or ∼315 µg RE/d to mothers and ∼55 µg RE/d to infants as provitamin A carotenoid-biofortified maize or retinyl palmitate-fortified maize. Outcomes were TBS, measured by retinol isotope dilution in infants (primary), and breast milk retinol, measured by HPLC in women (secondary). RESULTS The intervention groups were comparable at baseline. Loss to follow-up was 10% (n = 230 mother-infant pairs). Women consumed 92% of the intended 287 g/d and infants consumed 82% of the intended 50 g/d maize. The baseline geometric mean (GM) milk retinol concentration was 1.57 μmol/L (95% CI: 1.45, 1.69 μmol/L), and 24% of women had milk retinol <1.05 μmol/L. While mean milk retinol did not change in the biofortified arm (β: 0.11; 95% CI: -0.02, 0.24), the intervention reduced low milk retinol (RR: 0.42; 95% CI: 0.21, 0.85). Fortified maize increased mean milk retinol (β: 0.17; 95% CI: 0.04, 0.30) and reduced the prevalence of low milk retinol (RR: 0.46; 95% CI: 0.25, 0.82). The baseline GM TBS was 178 μmol (95% CI: 166, 191 μmol). This increased by 24 µmol (± 136) over the 90-d intervention period, irrespective of treatment group. CONCLUSIONS Both biofortified and fortified maize consumption improved milk retinol concentration. This did not translate into greater infant TBS, most likely due to adequate TBS at baseline. This trial was registered at clinicaltrials.gov as NCT02804490.
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Affiliation(s)
- Amanda C Palmer
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Modou L Jobarteh
- Institute for Global Nutrition, Department of Nutrition, University of California, Davis, CA, USA
| | | | - Matthew D Greene
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Anthony Oxley
- Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Georg Lietz
- Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Rose Mwanza
- Provincial Medical Office for Central Province, Kabwe, Zambia
| | - Marjorie J Haskell
- Institute for Global Nutrition, Department of Nutrition, University of California, Davis, CA, USA
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11
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Green MH, Ford JL, Green JB. Development of a Compartmental Model to Investigate the Influence of Inflammation on Predictions of Vitamin A Total Body Stores by Retinol Isotope Dilution in Theoretical Humans. J Nutr 2021; 151:731-741. [PMID: 33484140 PMCID: PMC7948205 DOI: 10.1093/jn/nxaa407] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/13/2020] [Accepted: 11/23/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Inflammation, both acute and chronic, is associated with reductions in the synthesis of retinol-binding protein (RBP) and the concentration of retinol in plasma. Consequently, it is currently recommended that the retinol isotope dilution (RID) method not be used to estimate vitamin A total body stores (TBS) in subjects with inflammation. OBJECTIVES To apply compartmental analysis to study the effects of inflammation on hepatic apo-RBP input, plasma retinol pool size, and RID-predicted TBS in theoretical subjects with known steady state values for these parameters. METHODS We selected 6 previously generated hypothetical subjects who ingested a dose of stable isotope-labeled vitamin A (day 0). Starting with each subject's published steady state model for retinol tracer kinetics, we developed a parallel model for unlabeled retinol and RBP that incorporated links between these entities and tied liver retinol secretion to RBP availability. Then we perturbed the steady state model by initiating chronic or acute inflammation on day 0 or acute inflammation on day 3 or 9 and simulating results for RBP, plasma retinol, and TBS. RESULTS Chronic inflammation led to substantial reductions in RID-predicted TBS for at least 2 weeks after tracer administration. In contrast, acute inflammation induced on day 0 or 3 resulted in less dramatic impacts on TBS (37% or 20% reduction, respectively, from steady state levels, with levels rebounding by 14 days). When inflammation was induced 9 days after administration of the tracer, the effects on predicted TBS were minimal. Overall, for acute inflammation initiated at 0, 3, or 9 days, accurate predictions of TBS were obtained by 2 weeks. CONCLUSIONS Compartmental analysis can be applied in the novel way described here to study the influence of perturbations such as inflammation on predictions of vitamin A status using RID. Such an approach has potential value for studying other perturbations and different nutrients.
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Affiliation(s)
| | - Jennifer Lynn Ford
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
| | - Joanne Balmer Green
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
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12
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Kaliwile C, Michelo C, Sheftel J, Davis CR, Grahn M, Bwembya P, Simpungwe E, Mwanza S, Chileshe J, Tanumihardjo SA. Breast Milk-Derived Retinol Is a Potential Surrogate for Serum in the 13C-Retinol Isotope Dilution Test in Zambian Lactating Women with Vitamin A Deficient and Adequate Status. J Nutr 2021; 151:255-263. [PMID: 33245109 DOI: 10.1093/jn/nxaa320] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/06/2020] [Accepted: 09/23/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Vitamin A (VA) deficiency (VAD) affects ∼19 million pregnant women worldwide. The extent of VAD in Zambian women of reproductive age is unknown owing to lack of survey inclusion or the use of static serum retinol concentrations, a low-sensitivity biomarker. OBJECTIVES This cross-sectional study employed isotopic techniques to determine VA status with serum and milk among women aged 18-49 y (n = 197) either lactating with infants aged 0-24 mo or nonlactating with or without infants. METHODS Assistants were trained and piloted data collection. Demographic data, anthropometry, and relevant histories were obtained including malaria and anemia. For retinol isotope dilution (RID), baseline fasting blood and casual breast milk samples were collected before administration of 2.0 μmol 13C2-retinyl acetate and 24-h dietary recalls. On day 14, blood (n = 144) and milk (n = 66) were collected. Prevalence of total liver VA reserves (TLR) ≤0.10 μmol/g was defined as VAD with comparison to the DRI assumption of 0.07 μmol/g as minimally acceptable for North Americans. RESULTS When a 20% adjustment for dose lost to milk was made in the RID equation for lactation, mean total body VA stores (TBS) for lactating women were 25% lower than for nonlactating women (P < 0.01), which was not the case without adjustment (P = 0.3). Mean ± SD TLR for all women were 0.15 ± 0.11 μmol/g liver. Using retinol purified from breast milk instead of serum for RID analysis yielded similar TBS and TLR, which were highly correlated between methods (P < 0.0001). Serum retinol ≤0.70 μmol/L had 0% sensitivity using either VAD liver cutoff and milk retinol ≤1.0 μmol/L had 42% sensitivity for VAD at 0.10 μmol/g. CONCLUSIONS Determining accurate VA status among women of reproductive age, especially lactating women, forms a basis for extrapolation to the general population and informing policy development and program implementation.
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Affiliation(s)
- Chisela Kaliwile
- Public Health and Community Nutrition Unit, National Food and Nutrition Commission, Lusaka, Zambia
| | - Charles Michelo
- Epidemiology and Biostatistics Unit, Department of Public Health, School of Medicine, University of Zambia, Lusaka, Zambia.,Nutrition and Population Studies Unit, Department of Public Health, School of Medicine, University of Zambia, Lusaka, Zambia
| | - Jesse Sheftel
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Christopher R Davis
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael Grahn
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Phoebe Bwembya
- Epidemiology and Biostatistics Unit, Department of Public Health, School of Medicine, University of Zambia, Lusaka, Zambia.,Nutrition and Population Studies Unit, Department of Public Health, School of Medicine, University of Zambia, Lusaka, Zambia
| | | | - Sydney Mwanza
- Biomedical Sciences Department, Tropical Diseases Research Center, Ndola, Zambia
| | - Justin Chileshe
- Biomedical Sciences Department, Tropical Diseases Research Center, Ndola, Zambia
| | - Sherry A Tanumihardjo
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
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13
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Green MH, Green JB, Ford JL. Vitamin A Absorption Efficiency Determined by Compartmental Analysis of Postprandial Plasma Retinyl Ester Kinetics in Theoretical Humans. J Nutr 2020; 150:2223-2229. [PMID: 32614427 PMCID: PMC7398788 DOI: 10.1093/jn/nxaa176] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/25/2020] [Accepted: 05/28/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Better methods are needed for determining vitamin A absorption efficiency in humans to support development of dietary recommendations and to improve the accuracy of predictions of vitamin A status. OBJECTIVES We developed and evaluated a method for estimating vitamin A absorption efficiency based on compartmental modeling of theoretical data on postprandial plasma retinyl ester (RE) kinetics. METHODS We generated data on plasma RE and retinol kinetics (30 min to 8 h or 56 d, respectively) after oral administration of labeled vitamin A for 12 theoretical adults with a range of values assigned for vitamin A absorption (55-90%); we modeled all data to obtain best-fit values for absorption and other parameters using Simulation, Analysis, and Modeling software. We then modeled RE data only (16 or 10 samples), with or without added random error, and compared assigned to predicted absorption values. We also compared assigned values to areas under RE response curves (RE AUCs). RESULTS We confirmed that a unique value for vitamin A absorption cannot be identified by modeling plasma retinol tracer kinetics. However, when RE data were modeled, predicted vitamin A absorptions were within 1% of assigned values using data without error and within 12% when 5% error was included. When the sample number was reduced, predictions were still within 13% for 10 of the 12 subjects and within 23% overall. Assigned values for absorption were not correlated with RE AUC (P = 0.21). CONCLUSIONS We describe a feasible and accurate method for determining vitamin A absorption efficiency that is based on compartmental modeling of plasma RE kinetic data collected for 8 h after a test meal. This approach can be used in a clinical setting after fasting subjects consume a fat-containing breakfast meal with a known amount of vitamin A or a stable isotope label.
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Affiliation(s)
| | - Joanne Balmer Green
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
| | - Jennifer Lynn Ford
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
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14
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Green MH, Green JB. Vitamin A Absorption Determined in Rats Using a Plasma Isotope Ratio Method. J Nutr 2020; 150:1977-1981. [PMID: 32271921 PMCID: PMC7330459 DOI: 10.1093/jn/nxaa092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/10/2020] [Accepted: 03/16/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Better methods are needed for determining vitamin A absorption efficiency. OBJECTIVE Our objective was to measure vitamin A absorption in rats by adapting a plasma isotope ratio method previously used to determine cholesterol absorption. METHODS Male Sprague-Dawley rats [n = 14; 340 ± 16 g (mean ± SD)] received an oral tracer dose of [3H]retinyl acetate in oil plus an intravenous dose of [14C]vitamin A-labeled lymph prepared in a donor rat that had received [14C]retinyl acetate intraduodenally. Blood samples were collected on days 1, 2, 3, 6, 9, and 12, and plasma was analyzed for 3H and 14C; vitamin A absorption was calculated for each sample as (fraction of oral dose/fraction of intravenous dose) × 100. Radioactivity was also measured in feces and urine collected as pools on days 3, 6, 9, and 12 and in liver and remaining carcass on day 12. RESULTS Vitamin A absorption calculated as the plasma isotope ratio was >100% on day 1, 78% ± 5% on day 6, 76% ± 5% on day 9, and 74% ± 5% on day 12; fitting the data to an exponential function plus a constant predicted an absorption of 75% by day 14. Recovery of the oral dose in feces (day 0 to day 6) was low (6.2% ± 0.84%, n = 10) and the mean isotope ratio in day 9-12 urine pool was lower than that in plasma. CONCLUSIONS The plasma isotope ratio holds promise for estimating vitamin A absorption, but additional work is needed to determine how long studies need to be and if the doses should be administered simultaneously. For application of this method in humans, artificial chylomicrons labeled with a stable isotope of retinyl acetate could be used for the intravenous dose, with a different isotope required for the oral dose.
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Affiliation(s)
| | - Joanne Balmer Green
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
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15
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Lopez-Teros V, Ford JL, Green MH, Monreal-Barraza B, García-Miranda L, Tanumihardjo SA, Valencia ME, Astiazaran-Garcia H. The "Super-Child" Approach Is Applied To Estimate Retinol Kinetics and Vitamin A Total Body Stores in Mexican Preschoolers. J Nutr 2020; 150:1644-1651. [PMID: 32135013 DOI: 10.1093/jn/nxaa048] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 01/08/2020] [Accepted: 02/12/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Retinol isotope dilution (RID) and model-based compartmental analysis are recognized techniques for assessing vitamin A (VA) status. Recent studies have shown that RID predictions of VA total body stores (TBS) can be improved by using modeling and that VA kinetics and TBS in children can be effectively studied by applying population modeling ("super-child" approach) to a composite data set. OBJECTIVES The objectives were to model whole-body retinol kinetics and predict VA TBS in a group of Mexican preschoolers using the super-child approach and to use model predictions of RID coefficients to estimate TBS by RID in individuals. METHODS Twenty-four healthy Mexican children (aged 3-6 y) received an oral dose (2.96 μmol) of [13C10]retinyl acetate in corn oil. Blood samples were collected from 8 h to 21 d after dosing, with each child sampled at 4 d and at 1 other time. Composite data for plasma labeled retinol compared with time were analyzed using a 6-component model to obtain group retinol kinetic parameters and pool sizes. Model-predicted TBS was compared with mean RID predictions at 4 d; RID estimates at 4 d were compared with those calculated at 7-21 d. RESULTS Model-predicted TBS was 1097 μmol, equivalent to ∼2.4 y-worth of VA; using model-derived coefficients, group mean RID-predicted TBS was 1096 μmol (IQR: 836-1492 μmol). TBS at 4 d compared with a later time was similar (P = 0.33). The model predicted that retinol spent 1.5 h in plasma during each transit and recycled to plasma 13 times before utilization. CONCLUSIONS The super-child modeling approach provides information on whole-body VA kinetics and can be used with RID to estimate TBS at any time between 4 and 21 d postdose. The high TBS predicted for these children suggests positive VA balance, likely due to large-dose VA supplements, and warrants further investigation.
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Affiliation(s)
- Veronica Lopez-Teros
- Posgrado en Ciencias de la Salud (PCS), Universidad de Sonora, Hermosillo, Sonora, Mexico
| | - Jennifer L Ford
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Michael H Green
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Brianda Monreal-Barraza
- Department of Nutrition, Research Center for Food and Development, Hermosillo, Sonora, Mexico
| | - Lilian García-Miranda
- Posgrado en Ciencias de la Salud (PCS), Universidad de Sonora, Hermosillo, Sonora, Mexico
| | - Sherry A Tanumihardjo
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Mauro E Valencia
- Posgrado en Ciencias de la Salud (PCS), Universidad de Sonora, Hermosillo, Sonora, Mexico
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16
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Green MH, Green JB, Ford JL. Better Predictions of Vitamin A Total Body Stores by the Retinol Isotope Dilution Method Are Possible with Deeper Understanding of the Mathematics and by Applying Compartmental Modeling. J Nutr 2020; 150:989-993. [PMID: 31851323 PMCID: PMC7198291 DOI: 10.1093/jn/nxz321] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/13/2019] [Accepted: 12/03/2019] [Indexed: 12/26/2022] Open
Abstract
Retinol isotope dilution (RID) is a well-accepted technique for assessing vitamin A status [i.e., total body stores (TBS)]. Here, in an effort to increase understanding of the method, we briefly review RID equations and discuss their included variables and their coefficients (i.e., assumptions that account for the efficiency of absorption of an orally administered tracer dose of vitamin A, mixing of the dose with endogenous vitamin A, and loss due to utilization). Then, we focus on contributions of another technique, model-based compartmental analysis and especially the "super-person" approach, that advance the RID method. Specifically, we explain how adding this modeling component, which involves taking 1 additional blood sample from each subject, provides population-specific estimates for the RID coefficients that can be used in the equation instead of values derived from the literature; using model-derived RID coefficients results in improved confidence in predictions of TBS for both a group and its individuals. We note that work is still needed to identify the optimal time for applying RID in different groups and to quantify vitamin A absorption efficiency. Finally, we mention other contributions of modeling, including the use of theoretical data to verify the accuracy of RID predictions and the additional knowledge that model-based compartmental analysis provides about whole-body vitamin A kinetics.
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Affiliation(s)
- Michael H Green
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA,Address correspondence to MHG (e-mail: )
| | - Joanne Balmer Green
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
| | - Jennifer Lynn Ford
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
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17
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Effect of High-dose Vitamin A Supplementation in Children With Sickle Cell Disease: A Randomized, Double-blind, Dose-finding Pilot Study. J Pediatr Hematol Oncol 2020; 42:83-91. [PMID: 31764511 DOI: 10.1097/mph.0000000000001673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Suboptimal vitamin A status (serum retinol <30 µg/dL) is associated with poor clinical outcomes in children with the hemoglobin-SS disease (HbSS), and supplementation with the recommended daily allowance of retinol is ineffective in improving vitamin A status. In a single-center randomized blinded dose-finding pilot study, we compared vitamin A and nutritional status in children with HbSS to healthy children and explored the impact of high-dose supplementation on the primary outcome serum vitamin A status. Exploratory outcomes included hematologic, nutritional, immunologic, and muscle function status in children with HbSS. A mixed-effects linear regression model evaluated associations between vitamin A dose, serum retinol, and exploratory outcomes. Twenty healthy children participated, and 22 subjects with HbSS were randomized to oral 3000 or 6000 IU/d retinol for 8 weeks; 21 subjects completed all evaluations. Serum retinol, growth, and nutritional status were all suboptimal in HbSS subjects at baseline, and supplementation did not change vitamin A status. Fetal hemoglobin (Δ=2.5, 95% confidence interval [CI], 0.5-4.3), mean corpuscular volume (Δ=2.7, 95% CI, 0.7-4.7), mean corpuscular hemoglobin (Δ=1.4, 95% CI, 0.5-2.3), and mean corpuscular hemoglobin concentration (Δ=0.5, 95% CI, 0.1-0.9) all improved with supplementation. Mild improvements in erythrocyte indices, growth status, and muscle function occurred independent of hydroxyurea use.
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18
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Ford JL, Green JB, Haskell MJ, Ahmad SM, Mazariegos Cordero DI, Oxley A, Engle-Stone R, Lietz G, Green MH. Use of Model-Based Compartmental Analysis and a Super-Child Design to Study Whole-Body Retinol Kinetics and Vitamin A Total Body Stores in Children from 3 Lower-Income Countries. J Nutr 2020; 150:411-418. [PMID: 31535129 PMCID: PMC7004890 DOI: 10.1093/jn/nxz225] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/30/2019] [Accepted: 08/23/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Model-based compartmental analysis has been used to describe and quantify whole-body vitamin A metabolism and estimate total body stores (TBS) in animals and humans. OBJECTIVES We applied compartmental modeling and a super-child design to estimate retinol kinetic parameters and TBS for young children in Bangladesh, Guatemala, and the Philippines. METHODS Children ingested [13C10]retinyl acetate and 1 or 2 blood samples were collected from each child from 6 h to 28 d after dosing. Temporal data for fraction of dose in plasma [13C10]retinol were modeled using WinSAAM software and a 6-component model with vitamin A intake included as weighted data. RESULTS Model-predicted TBS was 198, 533, and 1062 μmol for the Bangladeshi (age, 9-17 mo), Filipino (12-18 mo), and Guatemalan children (35-65 mo). Retinol kinetics were similar for Filipino and Guatemalan groups and generally faster for Bangladeshi children, although fractional transfer of plasma retinol to a larger exchangeable storage pool was the same for the 3 groups. Recycling to plasma from that pool was ∼2.5 times faster in the Bangladeshi children compared with the other groups and the recycling number was 2-3 times greater. Differences in kinetics between groups are likely related to differences in vitamin A stores and intakes (geometric means: 352, 727, and 764 μg retinol activity equivalents/d for the Bangladeshi, Filipino, and Guatemalan children, respectively). CONCLUSIONS By collecting 1 or 2 blood samples from each child to generate a composite plasma tracer data set with a minimum of 5 children/time, group TBS and retinol kinetics can be estimated in children by compartmental analysis; inclusion of vitamin A intake data increases confidence in model predictions. The super-child modeling approach is an effective technique for comparing vitamin A status among children from different populations. These trials were registered at www.clinicaltrials.gov as NCT03000543 (Bangladesh), NCT03345147 (Guatemala), and NCT03030339 (Philippines).
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Affiliation(s)
- Jennifer Lynn Ford
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
| | - Joanne Balmer Green
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA
| | - Marjorie J Haskell
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, Davis, CA, USA
| | - Shaikh M Ahmad
- International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Dora Inés Mazariegos Cordero
- Laboratorio de Bioquímica Nutricional, Unidad de Nutrición y Micronutrientes, Instituto de Nutrición de Centroamérica y Panamá, Guatemala City, Guatemala
| | - Anthony Oxley
- Human Nutrition Research Centre, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Reina Engle-Stone
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, Davis, CA, USA
| | - Georg Lietz
- Human Nutrition Research Centre, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Michael H Green
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA,Address correspondence to MHG (e-mail: )
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van Stuijvenberg ME, Dhansay MA, Nel J, Suri D, Grahn M, Davis CR, Tanumihardjo SA. South African preschool children habitually consuming sheep liver and exposed to vitamin A supplementation and fortification have hypervitaminotic A liver stores: a cohort study. Am J Clin Nutr 2019; 110:91-101. [PMID: 31089689 DOI: 10.1093/ajcn/nqy382] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/12/2018] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND In some regions, multiple vitamin A (VA) interventions occur in the same target groups, which may lead to excessive stores. Retinol isotope dilution (RID) is a more sensitive technique than serum retinol to measure VA status. OBJECTIVE We evaluated VA status before and after a high-dose supplement in preschool children living in a region in South Africa with habitual liver consumption and exposed to VA supplementation and fortification. METHODS After baseline blood samples, subjects (46.7 ± 8.4 mo; n = 94) were administered 1.0 μmol [14,15]-13C2-retinyl acetate to estimate total liver retinol reserves by RID with a follow-up 14-d blood sample. Liver intake was assessed with a frequency questionnaire. In line with current practice, a routine 200,000 IU VA capsule was administered after the RID test. RID was repeated 1 mo later. Serum retinyl esters were evaluated using ultra-performance liquid chromatography. RESULTS At baseline, 63.6% of these children had hypervitaminosis A defined as total liver retinol reserves ≥1.0 μmol/g liver, which increased to 71.6% after supplementation (1.13 ± 0.43 to 1.29 ± 0.46 μmol/g; P < 0.001). Total serum VA as retinyl esters was elevated in 4.8% and 6.1% of children before and after supplementation. The odds of having hypervitaminosis A at baseline were higher in children consuming liver ≥1/mo (ratio 3.70 [95% CI: 1.08, 12.6]) and in children receiving 2 (4.28 [1.03, 17.9]) or 3 (6.45 [0.64, 65.41]) supplements in the past 12 mo. Total body stores decreased after the supplement in children in the highest quartile at baseline compared with children with lower stores, who showed an increase (P = 0.007). CONCLUSIONS In children, such as this cohort in South Africa, with adequate VA intake through diet, and overlapping VA fortification and supplementation, preschool VA capsule distribution should be re-evaluated. This trial was registered at https://clinicaltrials.gov/ct2/show/NCT02915731 as NCT02915731.
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Affiliation(s)
- Martha E van Stuijvenberg
- Non-Communicable Diseases Research Unit, South African Medical Research Council.,Division of Human Nutrition, Cape Town, South Africa
| | - Muhammad A Dhansay
- Burden of Disease Research Unit, South African Medical Research Council.,Division of Human Nutrition, Cape Town, South Africa.,Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - Jana Nel
- Integrated Nutrition Programme, Northern Cape Department of Health, Kimberley, South Africa
| | - Devika Suri
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI
| | - Michael Grahn
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI
| | - Christopher R Davis
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI
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20
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Garrod MG, Buchholz BA, Miller JW, Haack KW, Green R, Allen LH. Vitamin B12 Added as a Fortificant to Flour Retains High Bioavailability when Baked in Bread. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION B, BEAM INTERACTIONS WITH MATERIALS AND ATOMS 2019; 438:136-140. [PMID: 30555197 PMCID: PMC6290905 DOI: 10.1016/j.nimb.2018.05.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Vitamin B12 deficiency and depletion are common world-wide, particularly in populations that consume low amounts of animal source foods. WHO and the Food Fortification Initiative recommend that wheat flour be fortified with vitamin B12 in regions where intake of B12 is low. The purpose of this pilot study in five participants was to determine if fortification of flour with B12 produced a bread product with intact B12 still present and to determine if healthy elderly absorb sufficient B12 from bread fortified in this manner. High-purity crystalline 14C-B12 was dissolved in water and added to flour (2 μg B12 /100 g flour) in a bread maker and made into rolls (average 1.17 kBq (31.5 nCi) 14C-B12 in a total of 0.8 µg B12 per roll). Excess 14C first appeared in plasma 4 h after ingestion of the 14C fortified bread and plasma levels returned almost to background by 72 h. Measurement of 14C in plasma verified that the dose was absorbed into the systemic circulation. The cumulative % dose recovered in urine was 4.8-37.0% (mean = 20.1%). Most of the 14C label in the stool appeared by day 4, and the cumulative % dose recovered in stool was 24.5- 43.0% (mean = 31.8%). Bioavailability among the 5 participants, calculated by subtracting the sum of urinary and fecal 14C excretion from the administered dose, was 28.4-63.7% (mean = 48.0%). This study showed that when B12 is added as a fortificant to flour it survives the fermentation and baking processes, and retains ~ 50% bioavailability when fed in small doses to healthy subjects. The Recommended Dietary Allowance of B12 for adults is 2.4 μg/d. This recommendation assumes that usual bioavailability of low doses of the vitamin in the crystalline form is 60%, while for the same amount in foods such as meat and fish it is 50%. Our pilot study shows that B12 added to bread as a fortificant in flour was absorbed as well as it is from endogenous food sources such as meat and fish.
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Affiliation(s)
- Marjorie G Garrod
- USDA, ARS Western Human Nutrition Research Center, Davis, California
| | - Bruce A Buchholz
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, California
| | - Joshua W Miller
- School of Environmental and Biological Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Kurt W Haack
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, California
| | - Ralph Green
- Dept. of Medical Pathology and Laboratory Medicine, University of California, Davis, California
| | - Lindsay H Allen
- USDA, ARS Western Human Nutrition Research Center, Davis, California
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Sheftel J, Loechl C, Mokhtar N, Tanumihardjo SA. Use of Stable Isotopes to Evaluate Bioefficacy of Provitamin A Carotenoids, Vitamin A Status, and Bioavailability of Iron and Zinc. Adv Nutr 2018; 9:625-636. [PMID: 30239582 PMCID: PMC6140444 DOI: 10.1093/advances/nmy036] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/25/2018] [Accepted: 05/14/2018] [Indexed: 01/25/2023] Open
Abstract
The ability of nutrition scientists to measure the status, bioavailability, and bioefficacy of micronutrients is affected by lack of access to the parts of the body through which a nutrient may travel before appearing in accessible body compartments (typically blood or urine). Stable isotope-labeled tracers function as safe, nonradioactive tools to follow micronutrients in a quantitative manner because the absorption, distribution, metabolism, and excretion of the tracer are assumed to be similar to the unlabeled vitamin or mineral. The International Atomic Energy Agency (IAEA) supports research on the safe use of stable isotopes in global health and nutrition. This review focuses on IAEA's contributions to vitamin A, iron, and zinc research. These micronutrients are specifically targeted by the WHO because of their importance in health and worldwide prevalence of deficiency. These 3 micronutrients are included in food fortification and biofortification efforts in low- and middle-income regions of the world. Vitamin A isotopic techniques can be used to evaluate the efficacy and effectiveness of interventions. For example, total body retinol stores were estimated by using 13C2-retinol isotope dilution before and after feeding Zambian children maize biofortified with β-carotene to determine if vitamin A reserves were improved by the intervention. Stable isotopes of iron and zinc have been used to determine mineral bioavailability. In Thailand, ferrous sulfate was better absorbed from fish sauce than was ferrous lactate or ferric ammonium citrate, determined with the use of different iron isotopes in each compound. Comparisons of one zinc isotope injected intravenously with another isotope taken orally from a micronutrient powder proved that the powder increased total absorbed zinc from a meal in Pakistani infants. Capacity building by the IAEA with appropriate collaborations in low- and middle-income countries to use stable isotopes has resulted in many advancements in human nutrition.
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Affiliation(s)
- Jesse Sheftel
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin–Madison, Madison, WI
| | | | | | - Sherry A Tanumihardjo
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin–Madison, Madison, WI
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Gannon BM, Valentine AR, Davis CR, Howe JA, Tanumihardjo SA. Duration of Retinol Isotope Dilution Studies with Compartmental Modeling Affects Model Complexity, Kinetic Parameters, and Calculated Vitamin A Stores in US Women. J Nutr 2018; 148:1387-1396. [PMID: 30137477 PMCID: PMC6075605 DOI: 10.1093/jn/nxy095] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 02/26/2018] [Accepted: 04/11/2018] [Indexed: 11/14/2022] Open
Abstract
Background Retinol isotope dilution (RID) indirectly estimates vitamin A (VA) status. Multicompartment modeling of RID data is used to refine study designs and equations to calculate VA stores. Previous studies suggest that VA in slowly turning over pools is not traced if follow-up is not long enough; however, shorter RID studies are being investigated. Few long-term models have been published. Objective We determined the effect of time on mathematical models of VA kinetics, model parameters, and outcomes. Methods In this longitudinal study, women (mean ± SD age: 22 ± 3 y; n = 7) were given 2.0 µmol [14,15]-13C2-retinyl acetate. Blood samples were staggered from 4 h to 152 d; the fraction of dose in serum was modeled with compartmental models. Four model-time categories were created: full models that used all data (median: 137 d; range 97-152 d) and truncated shorter studies of 14, 27, and 52 d (range: 42-62 d). Outcomes included number of compartments to adequately model serum data, kinetic parameters, total traced VA mass, and time-to-dose equilibration. To gain insight into longer follow-up, an additional participant was given 17.5 µmol 13C4-VA, and data were modeled as long as enrichment was above baseline (5 y). Results Longer follow-up times affected kinetic parameters and outcomes. Compared with the 14-d models, long-term full models required an additional compartment for adequate fit (14.3% compared with 100%; P = 0.0056) and had longer [median (quartile 1, quartile 3)] whole-body half-life [15.0 d (10.5, 72.6 d) compared with 135 d (115, 199 d); P = 0.0006], time-to-dose equilibration [3.40 d (3.14, 6.75 d) compared with 18.9 d (11.2, 25.7 d); P < 0.0001], and total traced mass [166 µmol VA (162, 252 µmol VA) compared with 476 µmol VA (290, 752 µmol VA); P = 0.0031]. Conclusions Extended RID sampling alters numerous mathematically modeled, time-dependent outcomes in women. Length of study should be considered when using mathematical models for calculating total-body VA stores or kinetic parameters related to VA turnover. This study is registered at www.clinicaltrials.gov as NCT03248700.
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Affiliation(s)
- Bryan M Gannon
- University of Wisconsin-Madison, Interdepartmental Graduate Program in Nutritional Sciences, Department of Nutritional Sciences, Madison, WI
| | - Ashley R Valentine
- University of Wisconsin-Madison, Interdepartmental Graduate Program in Nutritional Sciences, Department of Nutritional Sciences, Madison, WI
| | - Christopher R Davis
- University of Wisconsin-Madison, Interdepartmental Graduate Program in Nutritional Sciences, Department of Nutritional Sciences, Madison, WI
| | - Julie A Howe
- University of Wisconsin-Madison, Interdepartmental Graduate Program in Nutritional Sciences, Department of Nutritional Sciences, Madison, WI
| | - Sherry A Tanumihardjo
- University of Wisconsin-Madison, Interdepartmental Graduate Program in Nutritional Sciences, Department of Nutritional Sciences, Madison, WI
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Engle-Stone R, Perkins A, Clermont A, Walker N, Haskell MJ, Vosti SA, Brown KH. Estimating Lives Saved by Achieving Dietary Micronutrient Adequacy, with a Focus on Vitamin A Intervention Programs in Cameroon. J Nutr 2017; 147:2194S-2203S. [PMID: 28904117 DOI: 10.3945/jn.116.242271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/30/2016] [Accepted: 02/15/2017] [Indexed: 11/14/2022] Open
Abstract
Background: We previously compared the potential effects of different intervention strategies for achieving dietary vitamin A (VA) adequacy. The Lives Saved Tool (LiST) permits estimates of lives saved through VA interventions but currently only considers periodic VA supplements (VASs).Objective: We aimed to adapt the LiST method for estimating the mortality impact of VASs to estimate the impact of other VA interventions (e.g., food fortification) on child mortality and to estimate the number of lives saved by VA interventions in 3 macroregions in Cameroon.Methods: We used national dietary intake data to predict the effects of VA intervention programs on the adequacy of VA intake. LiST parameters of population affected fraction and intervention coverage were replaced with estimates of prevalence of inadequate intake and effective coverage (proportion achieving adequate VA intake). We used a model of liver VA stores to derive an estimate of the mortality reduction from achieving dietary VA adequacy; this estimate and a conservative assumption of equivalent mortality reduction for VAS and VA intake were applied to projections for Cameroon.Results: There were 2217-3048 total estimated VA-preventable deaths in year 1, with 58% occurring in the North macroregion. The relation between effective coverage and lives saved differed by year and macroregion due to differences in total deaths, diarrhea burden, and prevalence of low VA intake. Estimates of lives saved by VASs (the intervention common to both methods) were similar with the use of the adapted method (in 2012: North, 743-1021; South, 280-385; Yaoundé and Douala, 146-202) and the "usual" LiST method (North: 697; South: 381; Yaoundé and Douala: 147).Conclusions: Linking effective coverage estimates with an adapted LiST method permits estimation of the effects of combinations of VA programs (beyond VASs only) on child mortality to aid program planning and management. Rigorous program monitoring and evaluation are necessary to confirm predicted impacts.
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Affiliation(s)
| | - Amanda Perkins
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and
| | - Adrienne Clermont
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and
| | - Neff Walker
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and
| | | | - Stephen A Vosti
- Agricultural and Resource Economics, University of California, Davis, Davis, CA
| | - Kenneth H Brown
- Departments of Nutrition and.,Nutrition and Global Development, Bill & Melinda Gates Foundation, Seattle, WA
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Rubin LP, Ross AC, Stephensen CB, Bohn T, Tanumihardjo SA. Metabolic Effects of Inflammation on Vitamin A and Carotenoids in Humans and Animal Models. Adv Nutr 2017; 8:197-212. [PMID: 28298266 PMCID: PMC5347109 DOI: 10.3945/an.116.014167] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The association between inflammation and vitamin A (VA) metabolism and status assessment has been documented in multiple studies with animals and humans. The relation between inflammation and carotenoid status is less clear. Nonetheless, it is well known that carotenoids are associated with certain health benefits. Understanding these relations is key to improving health outcomes and mortality risk in infants and young children. Hyporetinolemia, i.e., low serum retinol concentrations, occurs during inflammation, and this can lead to the misdiagnosis of VA deficiency. On the other hand, inflammation causes impaired VA absorption and urinary losses that can precipitate VA deficiency in at-risk groups of children. Many epidemiologic studies have suggested that high dietary carotenoid intake and elevated plasma concentrations are correlated with a decreased risk of several chronic diseases; however, large-scale carotenoid supplementation trials have been unable to confirm the health benefits and in some cases resulted in controversial results. However, it has been documented that dietary carotenoids and retinoids play important roles in innate and acquired immunity and in the body's response to inflammation. Although animal models have been useful in investigating retinoid effects on developmental immunity, it is more challenging to tease out the effects of carotenoids because of differences in the absorption, kinetics, and metabolism between humans and animal models. The current understanding of the relations between inflammation and retinoid and carotenoid metabolism and status are the topics of this review.
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Affiliation(s)
- Lewis P Rubin
- Texas Tech Health Sciences Center El Paso, El Paso, TX
| | | | | | - Torsten Bohn
- Luxembourg Institute of Health, Population Health Department, Strassen, Luxembourg; and
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Lietz G, Furr HC, Gannon BM, Green MH, Haskell M, Lopez-Teros V, Novotny JA, Palmer AC, Russell RM, Tanumihardjo SA, Van Loo-Bouwman CA. Current Capabilities and Limitations of Stable Isotope Techniques and Applied Mathematical Equations in Determining Whole-Body Vitamin A Status. Food Nutr Bull 2016; 37:S87-S103. [PMID: 27053491 DOI: 10.1177/0379572116630642] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Retinol isotope dilution (RID) methodology provides a quantitative estimate of total body vitamin A (VA) stores and is the best method currently available for assessing VA status in adults and children. The methodology has also been used to test the efficacy of VA interventions in a number of low-income countries. Infections, micronutrient deficiencies (eg, iron and zinc), liver disease, physiological age, pregnancy, and lactation are known or hypothesized to influence the accuracy of estimating total body VA stores using the isotope dilution technique. OBJECTIVE Our objectives were to review the strengths and limitations of RID methods, to discuss what is known about the impact of various factors on results, and to summarize contributions of model-based compartmental analysis to assessing VA status. METHODS Relevant published literature is reviewed and discussed. RESULTS Various equations and compartmental modeling have been used to estimate the total body VA stores using stable isotopes, including a newer 3-day equation that provides an estimate of total body VA stores in healthy adults. At present, there is insufficient information on absorption of the isotope tracer, and there is a need to further investigate how various factors impact the application of RID techniques in field studies. CONCLUSIONS Isotope dilution methodology can provide useful estimates of total body VA stores in apparently healthy populations under controlled study conditions. However, more research is needed to determine whether the method is suitable for use in settings where there is a high prevalence of infection, iron deficiency, and/or liver disease.
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Affiliation(s)
- Georg Lietz
- Newcastle University, Newcastle, United Kingdom
| | | | | | - Michael H Green
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Marjorie Haskell
- Program in International and Community Nutrition and Department of Nutrition, University of California, Davis, CA, USA
| | | | - Janet A Novotny
- Beltsville Human Nutrition Research Center, United States Department of Agriculture, Beltsville, MD, USA
| | - Amanda C Palmer
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Tanumihardjo SA, Mokhtar N, Haskell MJ, Brown KH. Assessing the Safety of Vitamin A Delivered Through Large-Scale Intervention Programs: Workshop Report on Setting the Research Agenda. Food Nutr Bull 2016; 37:S63-74. [PMID: 26893060 DOI: 10.1177/0379572116630480] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Vitamin A (VA) deficiency (VAD) is still a concern in many parts of the world, and multiple intervention strategies are being implemented to reduce the prevalence of VAD and associated morbidity and mortality. Because some individuals within a population may be exposed to multiple VA interventions, concerns have been raised about the possible risk of hypervitaminosis A. OBJECTIVES A consultative meeting was held in Vienna, Austria, in March 2014 to (1) review current knowledge concerning the safety and effectiveness of large-scale programs to control VAD, (2) develop a related research agenda, and (3) review current available methods to assess VA status and risk of hypervitaminosis A. METHODS Multiple countries were represented and shared their experiences using a variety of assessment methods, including retinol isotope dilution (RID) techniques. Discussion included next steps to refine assessment methodology, investigate RID limitations under different conditions, and review programmatic approaches to ensure VA adequacy and avoid excessive intakes. RESULTS Fortification programs have resulted in adequate VA status in Guatemala, Zambia, and parts of Cameroon. Dietary patterns in several countries revealed that some people may consume excessive preformed VA from fortified foods. CONCLUSION Additional studies are needed to compare biomarkers of tissue damage to RID methods during hypervitaminosis A and to determine what other biomarkers can be used to assess excessive preformed VA intake.
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Affiliation(s)
- Sherry A Tanumihardjo
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Najat Mokhtar
- Technical Cooperation Department, International Atomic Energy Agency, Vienna, Austria
| | - Marjorie J Haskell
- Program in International and Community Nutrition and Department of Nutrition, University of California-Davis, Davis, CA, USA
| | - Kenneth H Brown
- Program in International and Community Nutrition and Department of Nutrition, University of California-Davis, Davis, CA, USA Nutrition Team, Bill & Melinda Gates Foundation, Seattle, WA, USA
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Engle-Stone R, Nankap M, Ndjebayi AO, Vosti SA, Brown KH. Estimating the Effective Coverage of Programs to Control Vitamin A Deficiency and Its Consequences Among Women and Young Children in Cameroon. Food Nutr Bull 2015; 36:S149-71. [PMID: 26385984 DOI: 10.1177/0379572115595888] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND To compare the cost-effectiveness of nutrition programs, the anticipated nutritional benefits of each intervention must be expressed using a common metric. OBJECTIVE We present the methodology for estimating the benefits of vitamin A (VA)-related interventions among women and children in Cameroon. METHODS We estimated "reach" (proportion of the population that receives a program), "coverage" (proportion that is deficient and receives a program), and "effective coverage" (proportion that "converts" from inadequate to adequate VA intake following an intervention) using dietary data collected during a national survey in 3 macro-regions of Cameroon (North, South, and Yaoundé/Douala). Effective coverage of programs such as (bio)fortification and micronutrient powders was estimated by adding the dietary VA contributed by the intervention to baseline VA intakes, including the contribution of increased maternal VA intake to infant VA intake through increases in breast milk VA. For interventions that provide VA-related benefits through other pathways (eg, periodic high-dose VA supplements and deworming), we developed alternative methods of estimating "daily VA intake equivalents. " RESULTS Baseline VA intakes and intervention reach varied by geographic macro-region. On average, estimates of program reach were greater than the effective coverage estimates by ∼50%. Effective coverage varied by intervention package and macro-region, ranging from <20 000 (deworming, Yaoundé/Douala) to >400 000 (micronutrient powder or VA supplement, North) children effectively covered per year. CONCLUSION These estimates of effective coverage, along with macro-region-specific information on the costs of each intervention package, serve as inputs into an economic optimization model to identify the most cost-effective package of VA interventions for each macro-region of Cameroon.
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Affiliation(s)
- Reina Engle-Stone
- Department of Nutrition, University of California-Davis, Davis, CA, USA
| | | | | | - Stephen A Vosti
- Department of Agricultural and Resource Economics, University of California-Davis, Davis, CA, USA
| | - Kenneth H Brown
- Department of Nutrition, University of California-Davis, Davis, CA, USA Bill & Melinda Gates Foundation, Seattle, WA, USA
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Lietz G, Haskell M, Melse-Boonstra A. Uncertainties of assessing total body vitamin A stores in community settings in low-income countries using the stable-isotope dilution methodology. Am J Clin Nutr 2015; 102:520-1. [PMID: 26240192 PMCID: PMC4515866 DOI: 10.3945/ajcn.115.110825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Georg Lietz
- From the Human Nutrition Research Centre, School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne, United Kingdom (GL, e-mail: ); the Program in International and Community Nutrition and Department of Nutrition, University of California, Davis, CA (MH); and the Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands (AM-B)
| | - Marjorie Haskell
- From the Human Nutrition Research Centre, School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne, United Kingdom (GL, e-mail: ); the Program in International and Community Nutrition and Department of Nutrition, University of California, Davis, CA (MH); and the Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands (AM-B)
| | - Alida Melse-Boonstra
- From the Human Nutrition Research Centre, School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne, United Kingdom (GL, e-mail: ); the Program in International and Community Nutrition and Department of Nutrition, University of California, Davis, CA (MH); and the Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands (AM-B)
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Gannon B, Kaliwile C, Arscott SA, Schmaelzle S, Chileshe J, Kalungwana N, Mosonda M, Pixley K, Masi C, Tanumihardjo SA. Biofortified orange maize is as efficacious as a vitamin A supplement in Zambian children even in the presence of high liver reserves of vitamin A: a community-based, randomized placebo-controlled trial. Am J Clin Nutr 2014; 100:1541-50. [PMID: 25411289 PMCID: PMC4232019 DOI: 10.3945/ajcn.114.087379] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 09/08/2014] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Biofortification is a strategy to relieve vitamin A (VA) deficiency. Biofortified maize contains enhanced provitamin A concentrations and has been bioefficacious in animal and small human studies. OBJECTIVE The study sought to determine changes in total body reserves (TBRs) of vitamin A with consumption of biofortified maize. DESIGN A randomized, placebo-controlled biofortified maize efficacy trial was conducted in 140 rural Zambian children. The paired (13)C-retinol isotope dilution test, a sensitive biomarker for VA status, was used to measure TBRs before and after a 90-d intervention. Treatments were white maize with placebo oil (VA-), orange maize with placebo (orange), and white maize with VA in oil [400 μg retinol activity equivalents (RAEs) in 214 μL daily] (VA+). RESULTS In total, 133 children completed the trial and were analyzed for TBRs (n = 44 or 45/group). Change in TBR residuals were not normally distributed (P < 0.0001); median changes (95% CI) were as follows: VA-, 13 (-19, 44) μmol; orange, 84 (21, 146) μmol; and VA+, 98 (24, 171) μmol. Nonparametric analysis showed no statistical difference between VA+ and orange (P = 0.34); both were higher than VA- (P = 0.0034). Median (95% CI) calculated liver reserves at baseline were 1.04 (0.97, 1.12) μmol/g liver, with 59% >1 μmol/g, the subtoxicity cutoff; none were <0.1 μmol/g, the deficiency cutoff. The calculated bioconversion factor was 10.4 μg β-carotene equivalents/1 μg retinol by using the middle 3 quintiles of change in TBRs from each group. Serum retinol did not change in response to intervention (P = 0.16) but was reduced with elevated C-reactive protein (P = 0.0029) and α-1-acid glycoprotein (P = 0.0023) at baseline. CONCLUSIONS β-Carotene from maize was efficacious when consumed as a staple food in this population and could avoid the potential for hypervitaminosis A that was observed with the use of preformed VA from supplementation and fortification. Use of more sensitive methods other than serum retinol alone, such as isotope dilution, is required to accurately assess VA status, evaluate interventions, and investigate the interaction of VA status and infection. This trial was registered at clinicaltrials.gov as NCT01814891.
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Affiliation(s)
- Bryan Gannon
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Chisela Kaliwile
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Sara A Arscott
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Samantha Schmaelzle
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Justin Chileshe
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Ngándwe Kalungwana
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Mofu Mosonda
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Kevin Pixley
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Cassim Masi
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
| | - Sherry A Tanumihardjo
- From the Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI (BG, SAA, SS, and SAT); National Food and Nutrition Commission of Zambia, Lusaka, Zambia (CK, MM, and CM); Tropical Diseases Research Centre, Ndola, Zambia (JC and NK); and International Maize and Wheat Improvement Center, Texcoco, Mexico (KP)
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Riabroy N, Tanumihardjo SA. Oral doses of α-retinyl ester track chylomicron uptake and distribution of vitamin A in a male piglet model for newborn infants. J Nutr 2014; 144:1188-95. [PMID: 24944285 DOI: 10.3945/jn.114.191668] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
α-Retinol has utility in determining chylomicron trafficking of vitamin A to tissues given that it will not be recirculated in blood on retinol binding protein (RBP). In this study, α-retinol was used as a chylomicron tag to investigate short-term uptake from high-dose supplements given to piglets as a model for neonates. The distribution of orally administered α-retinol doses in liver and extrahepatic tissues was assessed at varying times after dosing. Male piglets (n = 24 per group) from vitamin A-depleted sows were orally given 26.2 or 52.4 μmol of α-retinyl acetate, the molar equivalent of 25,000 and 50,000 IU of vitamin A, respectively. Tissues were collected and analyzed by HPLC. Lung (6.46 ± 2.94 nmol/g), spleen (22.1 ± 11.3 nmol/g), and adrenal gland (17.0 ± 11.2 nmol/g) α-retinol concentrations peaked at 7 h after dosing, and, by 7 d, α-retinol was essentially cleared from these tissues (≤0.25 ± 0.12 nmol/g). This demonstrates that the lung, spleen, and adrenal gland receive substantial vitamin A from chylomicra to maintain concentrations. Conversely, storage of α-retinol in the liver reached a plateau at 24 h (1.72 ± 0.58 μmol/liver) and was retained through 7 d (2.10 ± 0.38 μmol/liver) (P > 0.05). This indicates that α-retinol was not substantially utilized locally in the liver nor transported out from the liver via RBP. In serum, the majority of α-retinol was in the ester form, which confirms that α-retinol does not bind to RBP but does circulate. α-Retinyl esters were detectable at 7 d in the serum but were not different from baseline. Collectively, these data suggest that crucial immune organs need constant dietary intake to maintain vitamin A concentrations because α-retinol was quickly taken up by tissues and decreased to baseline in all tissues except long-term storage in the liver.
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Affiliation(s)
- Napaporn Riabroy
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI
| | - Sherry A Tanumihardjo
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI
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Abstract
Accelerator MS (AMS) provides a novel method for obtaining and analyzing pharmacokinetics and pharmacodynamics in children. This paper reviews the scientific and ethical rationale for AMS in pediatric trials, the regulatory framework and general considerations with some specific examples of pediatric clinical trials using AMS. Microdosing in the context of this article refers to studies using a negligible amount (nanocuries) of (14)C as tracer, and AMS as a quantitative technique. The technology is by no means a panacea for the deficiency in pediatric clinical research; however, it lessens the challenges and provides the most quantitative tool for pediatric pharmacology studies.
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Haskell MJ. The challenge to reach nutritional adequacy for vitamin A: β-carotene bioavailability and conversion--evidence in humans. Am J Clin Nutr 2012; 96:1193S-203S. [PMID: 23053560 DOI: 10.3945/ajcn.112.034850] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
β-Carotene is an important dietary source of vitamin A for humans. However, the bioavailability and vitamin A equivalency of β-carotene are highly variable and can be affected by food- and diet-related factors, including the food matrix, food-processing techniques, size of the dose of β-carotene, and the amounts of dietary fat, fiber, vitamin A, and other carotenoids in the diet as well as by characteristics of the target population, such as vitamin A status, nutrient deficiencies, gut integrity, and genetic polymorphisms associated with β-carotene metabolism. The absorption of β-carotene from plant sources ranges from 5% to 65% in humans. Vitamin A equivalency ratios for β-carotene to vitamin A from plant sources range from 3.8:1 to 28:1, by weight. Vitamin A equivalency ratios for β-carotene from biofortified Golden Rice or biofortified maize are 3.8:1 and 6.5:1, respectively, and are lower than ratios for vegetables that have more complex food matrices (10:1 to 28:1). The vitamin A equivalency of β-carotene is likely to be context-specific and dependent on specific food- and diet-related factors and the health, nutritional, and genetic characteristics of human populations. Although the vitamin A equivalency of β-carotene is highly variable, the provision of vegetable and fruit sources of β-carotene has significantly increased vitamin A status in women and children in community settings in developing countries; these results support the inclusion of dietary interventions with plant sources of β-carotene as a strategy for increasing vitamin A status in populations at risk of deficiency.
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Affiliation(s)
- Marjorie J Haskell
- Program in International and Community Nutrition, Nutrition Department, University of California, Davis, Davis, CA 95616, USA.
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Vitamin A intake and infection are associated with plasma retinol among pre-school children in rural Zambia. Public Health Nutr 2012; 15:1688-96. [PMID: 22443986 DOI: 10.1017/s1368980012000924] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To 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. DESIGN A 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. SETTING Rural communities in Central and Eastern Provinces of Zambia. SUBJECTS Children 2-5 years of age. RESULTS The 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. CONCLUSIONS Infection 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.
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Davidsson L, Tanumihardjo S. New frontiers in science and technology: nuclear techniques in nutrition. Am J Clin Nutr 2011; 94:691S-5S. [PMID: 21653797 PMCID: PMC3142739 DOI: 10.3945/ajcn.110.005819] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The use of nuclear techniques in nutrition adds value by the increased specificity and sensitivity of measures compared with conventional techniques in a wide range of applications. This article provides a brief overview of well-established stable-isotope techniques to evaluate micronutrient bioavailability and assess human-milk intake in breastfed infants to monitor the transfer of micronutrients from the mother to the infant. Recent developments are highlighted in the use of nuclear techniques to evaluate biological interactions between food, nutrition, and health to move the agenda forward.
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Affiliation(s)
- Lena Davidsson
- Nutritional and Health-Related Environmental Studies Section, Division of Human Health, International Atomic Energy Agency, Vienna International Centre, Vienna, Austria.
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Dueker SR, Vuong LT, Lohstroh PN, Giacomo JA, Vogel JS. Quantifying exploratory low dose compounds in humans with AMS. Adv Drug Deliv Rev 2011; 63:518-31. [PMID: 21047543 PMCID: PMC3062634 DOI: 10.1016/j.addr.2010.10.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 10/08/2010] [Accepted: 10/18/2010] [Indexed: 11/20/2022]
Abstract
Accelerator Mass Spectrometry is an established technology whose essentiality extends beyond simply a better detector for radiolabeled molecules. Attomole sensitivity reduces radioisotope exposures in clinical subjects to the point that no population need be excluded from clinical study. Insights in human physiochemistry are enabled by the quantitative recovery of simplified AMS processes that provide biological concentrations of all labeled metabolites and total compound related material at non-saturating levels. In this paper, we review some of the exploratory applications of AMS (14)C in toxicological, nutritional, and pharmacological research. This body of research addresses the human physiochemistry of important compounds in their own right, but also serves as examples of the analytical methods and clinical practices that are available for studying low dose physiochemistry of candidate therapeutic compounds, helping to broaden the knowledge base of AMS application in pharmaceutical research.
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