Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-10T14:39:48.625Z Has data issue: false hasContentIssue false
  • English
  • Français

Vitamin A and immunity to viral, bacterial and protozoan infections

Published online by Cambridge University Press:  28 February 2007

R. D. Semba
R. D. Semba*
Affiliation:
Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
*
Corresponding Author: Dr R. D. Semba, fax +1 410 955 0629, email rdsemba@jhmi.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Studies in animal models and cell lines show that vitamin A and related retinoids play a major role in immunity, including expression of mucins and keratins, lymphopoiesis, apoptosis, cytokine expression, production of antibody, and the function of neutrophils, natural killer cells, monocytes or macrophages, T lymphocytes and B lymphocytes. Recent clinical trials suggest that vitamin A supplementation reduces morbidity and mortality in different infectious diseases, such as measles, diarrhoeal disease, measles-related pneumonia, human immunodeficiency virus infection and malaria. Immune responses vary considerably during different infections, and the available data suggest that the modulation of immune function by vitamin A may also vary widely, depending on the type of infection and immune responses involved.

Keywords

Vitamin AImmunityInfectionMeaslesMalaria
Type
Symposium on ’Nutrition, infection and immunity‘
Information
Proceedings of the Nutrition Society , Volume 58 , Issue 3 , August 1999 , pp. 719 - 727
Copyright
Copyright © The Nutrition Society 1999

References

Aaby, P (1988) Malnutrition and overcrowding/intensive exposure in severe measles infection: review of community studies. Reviews of Infectious Disease 10, 478–491.CrossRefGoogle ScholarPubMed
Ahmed, F, Jones, DB & Jackson, AA (1990) The interaction of vitamin A deficiency and rotavirus infection in the mouse. British Journal of Nutrition 63, 363–373.CrossRefGoogle ScholarPubMed
Ahmed, F, Jones, DB & Jackson, AA (1991) Effect of vitamin A deficiency on the immune response to epizootic diarrhoea of infant mice (EDIM) rotavirus infection in mice. British Journal of Nutrition 65, 475–485.CrossRefGoogle ScholarPubMed
Alwar, AJE (1992) The effect of protein energy malnutrition on morbidity and mortality due to measles at Kenyatta National Hospital, Nairobi, Kenya. East African Medical Journal 69, 415–418.Google ScholarPubMed
Baird, JK (1998) Age-dependent characteristics of protection v. susceptibility to. Plasmodium falciparum. Annals of Tropical Medicine and Parasitology 92, 367–390.CrossRefGoogle ScholarPubMed
Barclay, AJG, Foster, A & Sommer, A (1987) Vitamin A supplements and mortality related to measles: a randomised clinical trial. British Medical Journal 323, 160–164.Google Scholar
Barreto, ML, Santos, LMP, Assis, AMO, Purificação, M, Araújo, N, Farenzena, GG, Santos, PAB & Fiaccone, RL (1994) Effect of vitamin A supplementation on diarrhoea and acute lower-respiratory-tract infections in young children in Brazil. Lancet 344, 228–231.CrossRefGoogle ScholarPubMed
Beaton, GH, Martorell, R, L’Abbe, KA, Edmonston, B, McCabe, G, Ross, AC & Harvey, B (1993) Effectiveness of Vitamin A Supplementation in the Control of Young Child Morbidity and Mortality in Developing Countries. ACC/SCN State-of-the-Art Nutrition Policy Discussion Paper no. 13. Geneva: UN.Google Scholar
Bellini, WJ, Rota, JS & Rota, PA (1994) Virology of measles virus. Journal of Infectious Diseases 170, Suppl. 1, S15–S23.CrossRefGoogle ScholarPubMed
Bernstein, DI, McNeal, MM, Schiff, GM & Ward, RL (1989) Induction and persistence of local rotavirus antibodies in relation to serum antibodies. Journal of Medical Virology 28, 90–95.CrossRefGoogle ScholarPubMed
Blackfan, KD & Wolbach, SG (1933) Vitamin A deficiency in infants: a clinical and pathological study. Journal of Pediatrics 3, 679–706.CrossRefGoogle Scholar
Bresee, JS, Fischer, M, Dowell, SF, Johnston, BD, Biggs, VM, Levine, RS, Lingappa, JR, Keyserling, HL, Petersen, KM, Bak, JR, Gary, HE, Sowell, AL, Rubens, CE & Anderson, LJ (1996) Vitamin A therapy for children with respiratory syncytial virus infection: a multicenter trial in the United States. Pediatric Infectious Diseases Journal 15, 777–782.CrossRefGoogle ScholarPubMed
Brilliant, LB, Pokhrel, RP, Grasset, NC, Lepkowski, JM, Kolstad, A, Hawks, W, Pararajasegaram, R, Brilliant, GE, Gilbert, S, Shrestha, SR & Kuo, J (1985) Epidemiology of blindness in Nepal. Bulletin of the World Health Organization 63, 375–386.Google ScholarPubMed
Cantorna, MT, Nashold, FE & Hayes, CE (1994) In vitamin A deficiency multiple mechanisms establish a regulatory T helper cell imbalance with excess Th1 and insufficient Th2 function. Journal of Immunology 152, 1515–1522.CrossRefGoogle ScholarPubMed
Cooper, AM, Magram, J, Ferrante, J & Orme, IM (1997) Interleukin 12 (IL-12) is crucial to the development of protective immunity in mice intravenously infected with Mycobacterium tuberculosis. Journal of Experimental Medicine 186, 39–45.CrossRefGoogle Scholar
Coulson, BS (1998) Long-itudinal studies of neutralizing antibody responses to rotavirus in stools and sera of children following severe rotavirus gastroenteritis. Clinical and Diagnostic Laboratory Immunology 5, 897–901.CrossRefGoogle Scholar
Coutsoudis, A, Bobat, RA, Coovadia, HM, Kuhn, L, Tsai, WY & Stein, ZA (1995) The effects of vitamin A supplementation on the morbidity of children born to HIV-infected women. American Journal of Public Health 85, 1076–1081.CrossRefGoogle ScholarPubMed
Coutsoudis, A, Broughton, M & Coovadia, HM (1991) Vitamin A supplementation reduces measles morbidity in young African children: a randomized, placebo-controlled, double-blind trial. American Journal of Clinical Nutrition 54, 890–895.CrossRefGoogle ScholarPubMed
Coutsoudis, A, Kiepiela, P, Coovadia, HM & Broughton, M (1992) Vitamin A supplementation enhances specific IgG antibody levels and total lymphocyte numbers while improving morbidity in measles. Pediatric Infectious Diseases Journal 11, 203–209.CrossRefGoogle ScholarPubMed
Dannenberg, AM Jr (1989) Immune mechanisms in the pathogenesis of pulmonary tuberculosis. Reviews of Infectious Diseases 11, Suppl. 2, S369–S378.CrossRefGoogle ScholarPubMed
DeSole, G, Belay, Y & Zegeye, B (1987) Vitamin A deficiency in southern Ethiopia. American Journal of Clinical Nutrition 45, 780–784.CrossRefGoogle Scholar
Dowell, SF, Papic, Z, Bresee, JS, Larrañaga, C, Mendez, M, Sowell, AL, Gary, HE, Anderson, LJ & Avendaño, LF (1996) Treatment of respiratory syncytial virus infection with vitamin A: a randomized, placebo-controlled trial in Santiago, Chile. Pediatric Infectious Diseases Journal 15, 782–786.CrossRefGoogle ScholarPubMed
Dudley, L, Hussey, G, Huskissen, J & Kessow, G (1997) Vitamin A status, other risk factors and acute respiratory infection morbidity in children. South African Medical Journal 87, 65–70.Google ScholarPubMed
Fawzi, WW, Mbise, RL, Fataki, MR, Herrera, MG, Kawau, F, Hertzmark, E, Spiegelman, D & Ndossi, G (1998 a) Vitamin A supplementation and severity of pneumonia in children admitted to the hospital in Dar es Salaam, Tanzania. American Journal of Clinical Nutrition 68, 187–192.CrossRefGoogle Scholar
Fawzi, W, Mbise, FL, Kawau, F, Herrera, MG, Hertzmark, E, Fataki, M & Spiegelman, G (1998 b) Vitamin A supplements and mortality among HIV positive and negative children in Tanzania. Abstracts of the 12th World AIDS Conference, Geneva, June 28-July 3, 1998, p. 840, Abstr. 170/42331, Geneva: 12th World Aids Conference Committee.Google Scholar
Fawzi, WW, Msamanga, GI, Spiegelman, D, Urassa, EJN, McGrath, N, Mwakagile, D, Antelman, G, Mbise, R, Herrera, G, Kapiga, S, Willett, W, Hunter, DJ & Tanzania Vitamin and HIV Infection Trial Team (1998 c) Randomised trial of effects of vitamin supplements on pregnancy outcomes and T cell counts in HIV-1-infected women in Tanzania. Lancet 351, 1477–1482.CrossRefGoogle Scholar
Ferraro, F, Mattei, M & Colizzi, V (1988) Low doses of recombinant interleukin-2 enhanced delayed type hypersensitivity to PPD in mice infected with Mycobacterium bovis-BCG and fed a diet supplemented with vitamin A acetate. Zeitschrift für Erkrankungen der Atmungsorgane 171, 45–49.Google ScholarPubMed
Finkelstein, MH (1932) Effect of carotene on course of B. tuberculosis infection of mice fed on a vitamin A deficient diet. Proceedings of the Society for Experimental Biology and Medicine 29, 69–71.Google Scholar
Friis, H, Mwaniki, D, Omondi, B, Muniu, E, Magnussen, P, Geissler, W, Thiong’o, F & Michaelsen, KF (1997) Serum retinol concentrations and Schistosoma mansoni intestinal helminths, and malarial parasitemia: a cross-sectional study in Kenyan preschool and primary school children. American Journal of Clinical Nutrition 66, 665–671.CrossRefGoogle ScholarPubMed
Galan, P, Samba, C, Luzeau, R & Amedee-Manesme, O (1990) Vitamin A deficiency in preschool age Congolese children during malaria attacks. Part 2: impact of parasitic disease on vitamin A status. International Journal of Vitamin and Nutrition Research 60, 224–228.Google ScholarPubMed
Gangopadhyay, NN, Moldoveanu, Z & Stephensen, CB (1996) Vitamin A deficiency has different effects on immunoglobulin A production and transport during influenza A infection in BALB/c mice. Journal of Nutrition 126, 2960–2967.CrossRefGoogle ScholarPubMed
Gloyne, SR & Page, DS (1921) A preliminary note on the relationship between deficiency in vitamin A and tuberculosis. Tubercle 3, 577–579.CrossRefGoogle Scholar
Göttgens, B & Green, AR (1995) Retinoic acid and the differentiation of lymphohaemapoietic stem cells. Bioessays 17, 187–189.CrossRefGoogle Scholar
Griffin, DE (1995) Immune responses during measles virus infection. Current Topics in Microbiology and Immunology 191, 117–134.Google ScholarPubMed
Grimwood, K, Lund, JC, Coulson, BS, Hudson, IL, Bishop, RF & Barnes, GL (1988) Comparison of serum and mucosal antibody responses following severe acute rotavirus gastroenteritis in young children. Journal of Clinical Microbiology 26, 732–738.CrossRefGoogle ScholarPubMed
Gujral, S, Abbi, R & Gopaldas, T (1993) Xerophthalmia, vitamin A supplementation and morbidity in children. Journal of Tropical Pediatrics 39, 89–92.CrossRefGoogle ScholarPubMed
Hanekom, WA, Potgieter, S, Hughes, EJ, Malan, H, Kessow, G & Hussey, GD (1997) Vitamin A status and therapy in childhood pulmonary tuberculosis. Journal of Pediatrics 131, 925–927.CrossRefGoogle ScholarPubMed
Hernández-Pando, R, Orozcoe, H, Sampieri, A, Pavón, L, Velasquillo, C, Larriva-Sahd, J, Alcocer, JM & Madrid, MV (1996) Correlation between the kinetics of Th1/Th2 cells and pathology in a murine model of experimental pulmonary tuberculosis. Immunology 89, 26–33.Google Scholar
Høgh, B (1996) Clinical and parasitological studies on immunity to Plasmodium falciparum malaria in children. Scandinavian Journal of Infectious Diseases 102, Suppl., 1–53.Google ScholarPubMed
Hossain, S, Biswas, R, Kabir, I, Sarker, S, Dibley, M, Fuchs, G & Mahalanabis, D (1998) Single dose vitamin A treatment in acute shigellosis in Bangladeshi children: randomised double blind controlled trial. British Medical Journal 316, 422–426.CrossRefGoogle Scholar
Hussey, G, Hughes, J, Potgieter, S, Kessow, G, Burgess, J, Beatty, D, Keraan, M & Carlesle, E (1996) Vitamin A status and supplementation and its effects on immunity in children with AIDS. In Abstracts of the XVII International Vitamin A Consultative Group Meeting, Guatemala City, p. 6. Washington, DC: International Life Sciences Institute.Google Scholar
Hussey, GD & Klein, M (1990) A randomized, controlled trial of vitamin A in children with severe measles. New England Journal of Medicine 323, 160–164.CrossRefGoogle ScholarPubMed
Karp, CL, Wysocka, M, Wahl, LM, Ahearn, JM, Cuomo, PJ, Sherry, B, Trinchieri, G & Griffin, DE (1996) Mechanism of suppression of cell-mediated immunity by measles virus. Science 273, 228–231.CrossRefGoogle ScholarPubMed
Kjolhede, CL, Chew, FJ, Gadomski, AM & Marroquin, DP (1995) Clinical trial of vitamin A as adjuvant treatment for lower respiratory tract infections. Journal of Pediatrics 126, 807–812.CrossRefGoogle ScholarPubMed
Lalvani, A, Brookes, R, Wilkinson, RJ, Malin, AS, Pathan, AA, Andersen, P, Dockrell, H, Pasvol, G & Hill, AVS (1998) Human cytolytic and interferon γ-secreting CD8+ T lymphocytes specific for Mycobacterium tuberculosis. Proceedings of the National Academy of Sciences USA 95, 270–275.CrossRefGoogle ScholarPubMed
McNeal, MM & Ward, RL (1995) Long-term production of rotavirus antibody and protection against reinfection following a single infection of neonatal mice with murine rotavirus. Virology 211, 474–480.CrossRefGoogle ScholarPubMed
Markowitz, L, Nzilambi, N, Driskell, WJ, Sension, MG, Rovira, EZ, Nieburg, P & Ryder, RW (1989) Vitamin A levels and mortality among hospitalized measles patients, Kinshasa, Zaire. Journal of Tropical Pediatrics 35, 109–112.CrossRefGoogle ScholarPubMed
Mitra, AK, Alvarez, JO, Guay-Woodford, L, Fuchs, GJ, Wahed, MA & Stephensen, CB (1998) Urinary retinol excretion and kidney function in children with shigellosis. American Journal of Clinical Nutrition 68, 1095–1103.CrossRefGoogle ScholarPubMed
Moriguchi, S, Werner, L & Watson, RR (1985) High dietary vitamin A (retinyl palmitate) and cellular immune functions in mice. Immunology 56, 169–177.Google ScholarPubMed
Muhe, L, Lulseged, S, Mason, KE & Simoes, EAF (1997) Case-control study of the role of nutritional rickets in the risk of developing pneumonia in Ethiopian children. Lancet 349, 1801–1804.CrossRefGoogle ScholarPubMed
Murphy, GS & Oldfield, EC (1996) Falciparum malaria. Infectious Disease Clinics of North America 10, 747–775.CrossRefGoogle ScholarPubMed
Nacul, LC, Kirkwood, BR, Arthur, P, Morris, SS, Magalhães, M & Fink, MCDS (1997) Randomised, double blind, placebo controlled clinical trial of efficacy of vitamin A treatment in non-measles childhood pneumonia. British Medical Journal 315, 505–510.CrossRefGoogle ScholarPubMed
Ogaro, FO, Orinda, VA, Onyango, FE & Black, RE (1993) Effect of vitamin A on diarrhoeal and respiratory complications of measles. Tropical and Geographical Medicine 45, 283–286.Google ScholarPubMed
Quinlan, KP & Hayani, KC (1996) Vitamin A and respiratory syncytial virus infection. Serum levels and supplementation trial. Archives of Pediatric and Adolescent Medicine 150, 25–30.CrossRefGoogle ScholarPubMed
Rahman, MM, Mahalanabis, D, Alvarez, JO, Wahed, MA, Islam, MA & Habte, D (1997) Effect of early vitamin A supplementation on cell-mediated immunity in infants younger than 6 mo. American Journal of Clinical Nutrition 65, 144–148.CrossRefGoogle Scholar
Rahman, MM, Mahalanabis, D, Alvarez, JO, Wahed, MA, Islam, MA, Habte, D & Khaled, MA (1996) Acute respiratory infections prevent improvement of vitamin A status in young infants supplemented with vitamin A. Journal of Nutrition 126, 628–633.CrossRefGoogle ScholarPubMed
Reeder, JC & Brown, GV (1996) Antigenic variation and immune evasion in Plasmodium falciparum malaria. Immunology and Cell Biology 74, 546–554.CrossRefGoogle ScholarPubMed
Roman, M, Calhoun, WJ, Hinton, KL, Avendano, LF, Simon, V, Escobar, AM, Gaggero, A & Diaz, PV (1997) Respiratory syncytial virus infection in infants is associated with predominant Th-2-like response. American Journal of Respiratory and Critical Care Medicine 156, 190–195.CrossRefGoogle ScholarPubMed
Ross, DA & Cutts, FT (1997) Vindication of policy of vitamin A with measles vaccination. Lancet 350, 81–82.CrossRefGoogle ScholarPubMed
Ruel, MT, Rivera, JA, Santizo, MC, Lonnerdal, B & Brown, KH (1997) Impact of zinc supplementation on morbidity from diarrhea and respiratory infections among Guatemalan children. Pediatrics 99, 808–813.CrossRefGoogle ScholarPubMed
Ryan, M, Gothefors, L, Storsaeter, J & Mills, KH (1997 a) Bordetella pertussis-specific Th1/Th2 cells generated following respiratory infection or immunization with an acellular vaccine: comparison of the T cell cytokine profiles in infants and mice. Developments in Biological Standardization 89, 297–305.Google ScholarPubMed
Ryan, M, Murphy, G, Gothefors, L, Nilsson, L, Storsaeter, J & Mills, KH (1997 b) Bordetella pertussis respiratory infection in children is associated with preferential activation of type 1 T helper cells. Journal of Infectious Diseases 175, 1246–1250.CrossRefGoogle ScholarPubMed
Schaumberg, DA, O’Connor, J & Semba, RD (1996) Risk factors for xerophthalmia in the Republic of Kiribati. European Journal of Clinical Nutrition 50, 761–764.Google ScholarPubMed
Semba, RD (1997) Vitamin A supplementation. Lancet 350, 1031–1032.CrossRefGoogle ScholarPubMed
Semba, RD (1998) The role of vitamin A and related retinoids in immune function. Nutrition Reviews 56, S38–S48.CrossRefGoogle ScholarPubMed
Semba, RD, Akib, A, Beeler, J, Munasir, Z, Permaesih, D, Muherdiyantiningsih, , Komala, , Martuti, S & Muhilal, (1997) Effect of vitamin A supplementation on measles vaccination in nine-month-old infants. Public Health 111, 245–247.CrossRefGoogle ScholarPubMed
Semba, RD, Lyles, CM, Margolick, JB, Caiaffa, WT, Farzadegan, H, Cohn, S & Vlahov, D (1998) Vitamin A supplementation and human immunodeficiency virus load in injection drug users. Journal of Infectious Diseases 177, 611–616.CrossRefGoogle ScholarPubMed
Semba, RD, Miotti, PG, Chiphangwi, JD, Saah, AJ, Canner, JK, Dallabetta, GA & Hoover, DR (1994) Maternal vitamin A deficiency and mother-to-child transmission of HIV-1. Lancet 343, 1593–1597.CrossRefGoogle ScholarPubMed
Semba, RD, Muhilal, , Scott, AL, Natadisastra, G, Wirasasmita, S, Mele, L, Ridwan, E, West, KP Jr & Sommer, A (1992) Depressed immune response to tetanus in children with vitamin A deficiency. Journal of Nutrition 122, 101–107.CrossRefGoogle ScholarPubMed
Semba, RD, Muhilal, , Ward, BJ, Griffin, DE, Scott, AL, Natadisastra, G, West, KP Jr & Sommer, A (1993) Abnormal T-cell subset proportions in vitamin A-deficient children. Lancet 341, 5–8.CrossRefGoogle ScholarPubMed
Semba, RD, Munasir, Z, Beeler, J, Akib, A, Muhilal, , Audet, S & Sommer, A (1995) Reduced seroconversion to measles in infants given vitamin A with measles vaccination. Lancet 345, 1330–1332.Google ScholarPubMed
Semba, RD, Park, S, Royal, W & Griffin, DE (1996) Vitamin A deficiency and T-cell subpopulations in HIV-infected adults. Nutrition Research 16, 915–923.CrossRefGoogle Scholar
Semba, RD & Tang, AM (1999) Micronutrients and the pathogenesis of human immunodeficiency virus infection. British Journal of Nutrition 81, 181–189.CrossRefGoogle ScholarPubMed
Shankar, AH, Genton, B, Semba, RD, Tielsch, J & West, KP Jr (1997) Vitamin A supplementation as a nutrient-based intervention to reduce malaria-related morbidity. In Abstracts of the XVIII International Vitamin A Consultative Group Meeting, Cairo, Egypt, p. 31.Washington, DC: The Human Nutrition Institute.Google Scholar
Sijtsma, SR, Rombout, JHWM, van der Zijpp, AJ & West, CE (1990) Vitamin A deficiency impairs cytotoxic T lymphocyte activity in Newcastle disease virus-infected chickens. Veterinary Immunology and Immunopathology 26, 191–201.CrossRefGoogle ScholarPubMed
Sklan, D, Melamed, D & Friedman, A (1994) The effect of varying levels of dietary vitamin A on immune response in the chick. Poultry Science 73, 843–847.CrossRefGoogle ScholarPubMed
Solotorovsky, M, Squibb, RL, Wogan, GN, Siegel, H & Gala, R (1961) The effect of dietary fat and vitamin A on avian tuberculosis in chicks. American Review of Respiratory Diseases 84, 226–235.Google Scholar
Sommer, A, Katz, J & Tarwotjo, I (1984) Increased risk of respiratory disease and diarrhea in children with preexisting mild vitamin A deficiency. American Journal of Clinical Nutrition 40, 1090–1095.CrossRefGoogle ScholarPubMed
Sommer, A & West, KP Jr (1996) Vitamin A Deficiency: Health, Survival, and Vision. New York: Oxford University Press.CrossRefGoogle Scholar
Sriramachari, S & Gopalan, C (1958) Nutrition and tuberculosis: effect of some nutritional factors on resistance to tuberculosis. Indian Journal of Medical Research 46, 105–112.Google ScholarPubMed
Stabell, Benn C, Aaby, P, Balé, C, Olsen, J, Michaelsen, KF, George, E & Whittle, H (1997) Randomised trial of effect of vitamin A supplementation on antibody response to measles vaccine in Guinea-Bissau, west Africa. Lancet 350, 101–105.Google Scholar
Stephensen, CB, Blount, SR, Schoeb, TR & Park, JY (1993) Vitamin A deficiency impairs some aspects of the host response to influenza A virus infection in BALB/c mice. Journal of Nutrition 123, 823–833.CrossRefGoogle ScholarPubMed
Stephensen, CB, Moldaveanu, Z & Gangopadhyay, NN (1996) Vitamin A deficiency diminishes the salivary immunoglobulin A response and enhances the serum immunoglobulin G response to influenza A virus infection in BALB/c mice. Journal of Nutrition 126, 94–102.CrossRefGoogle ScholarPubMed
Stoltzfus, RJ, Jalal, F, Harvey, PWJ & Nesheim, MC (1989) Interactions between vitamin A deficiency and Plasmodium berghei infection in the rat. Journal of Nutrition 119, 2030–2037.CrossRefGoogle ScholarPubMed
Stürchler, D, Tanner, M, Hanck, A, Betschart, B, Gautschi, K, Weiss, N, Burnier, E, Del Giudice, G & Degrémont, A (1987) A longitudinal study on relations of retinol with parasitic infections and the immune response in children of Kikwawila village, Tanzania. Acta Tropica 44, 213–227.Google ScholarPubMed
Sweet, LK & K’ang, HJ (1935) Clinical and anatomic study of avitaminosis A among the Chinese. American Journal of Diseases of Childhood 50, 699–734.Google Scholar
The Vitamin A and Pneumonia Working Group (1995) Potential interventions for the prevention of childhood pneumonia in developing countries: a meta-analysis of data from field trials to assess the impact of vitamin A supplementation on pneumonia morbidity and mortality. Bulletin of the World Health Organization 73, 609–619.Google Scholar
Tielsch, JM, West, KP, Katz, J, Chirambo, MC, Schwab, L, Johnson, GJ, Tizazu, T, Swartwood, J & Sommer, A (1986) Prevalence and severity of xerophthalmia in southern Malawi. American Journal of Epidemiology 124, 561–586.CrossRefGoogle ScholarPubMed
Wagner, G, Koram, K, McGuinness, D, Bennett, S, Nkrumah, F & Riley, E (1998) High incidence of asymptomatic malaria infections in a birth cohort of children less than one year of age in Ghana, detected by multicopy gene polymerase chain reaction. American Journal of Tropical Medicine and Hygiene 59, 115–123.CrossRefGoogle Scholar
Watson, RR, Yahya, MD, Darban, HR & Prabhala, RH (1988) Enhanced survival by vitamin A supplementation during a retrovirus infection causing murine AIDS. Life Sciences 43, 13–18.Google ScholarPubMed
West, CE, Rombout, JHWM, van der Zijpp, AJ & Sijtsma, SR (1991) Vitamin A and immune function. Proceedings of the Nutrition Society 50, 251–262.CrossRefGoogle ScholarPubMed
West, KP Jr, Katz, J, Shrestha, SR, LeClerq, SC, Khatry, SK, Pradhan, EK, Adhikari, R, Wu, LS, Pokhrel, RP & Sommer, A (1995) Mortality of infants <; 6 mo of age supplemented with vitamin A: a randomized, double-masked trial in Nepal. American Journal of Clinical Nutrition 62, 143–148.CrossRefGoogle ScholarPubMed
WHO/CHD Immunisation-Linked Vitamin A Supplementation Study Group (1998) Randomised trial to assess benefits and safety of vitamin A supplementation linked to immunisation in early infancy. Lancet 352, 1257–1263.CrossRefGoogle Scholar
Yoneda, T & Ellner, JJ (1998) CD4+ T cell and natural killer cell-dependent killing of Mycobacterium tuberculosis by human monocytes. American Journal of Respiratory and Critical Care Medicine 158, 395–403.CrossRefGoogle ScholarPubMed
Zhao, Z & Ross, AC (1995) Retinoic acid repletion restores the number of leukocytes and their subsets and stimulates natural cytotoxicity in vitamin A-deficient rats. Journal of Nutrition 125, 2064–2073.CrossRefGoogle ScholarPubMed