title: Vitamin A supplementation increases ratios of proinflammatory to anti-inflammatory cytokine responses in pregnancy and lactation.
abstract: Vitamin A supplementation reduces child mortality in populations at risk of vitamin A deficiency and may also reduce maternal mortality. One possible explanation for this is that vitamin A deficiency is associated with altered immune function and cytokine dysregulation. Vitamin A deficiency in pregnancy may thus compound the pregnancy-associated bias of cellular immune responses towards Th-2-like responses and exacerbate susceptibility to intracellular pathogens. We assessed mitogen and antigen-induced cytokine responses during pregnancy and lactation in Ghanaian primigravidae receiving either vitamin A supplementation or placebo. This was a double-blind, randomized, placebo-controlled trial of weekly vitamin A supplementation in pregnant and lactating women. Pregnancy compared to postpartum was associated with a suppression of cytokine responses, in particular of the proinflammatory cytokines interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha. Mitogen-induced TNF-alpha responses were associated with a decreased risk of peripheral parasitaemia during pregnancy. Furthermore, vitamin A supplementation was significantly associated with an increased ratio of mitogen-induced proinflammatory cytokine (IFN-gamma) to anti-inflammatory cytokine (IL-10) during pregnancy and in the postpartum period. The results of this study indicate that suppression of proinflammatory type 1 immune responses and hence immunity to intracellular infections, resulting from the combined effects of pregnancy and vitamin A deficiency, might be ameliorated by vitamin A supplementation.
authors.affiliation: Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine (LSHTM), London, UK. sharon.cox@lshtm.ac.uk
authors.forename: S E
authors.initials: SE
authors.lastname: Cox
authors.forename: P
authors.initials: P
authors.lastname: Arthur
authors.forename: B R
authors.initials: BR
authors.lastname: Kirkwood
authors.forename: K
authors.initials: K
authors.lastname: Yeboah-Antwi
authors.forename: E M
authors.initials: EM
authors.lastname: Riley
mesh_terms: D016207:Cytokines / Q000096:biosynthesis*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D007774:Lactation / Q000276:immunology*; D018512:Parasitemia / Q000276:immunology; D010835:Phytohemagglutinins / Q000276:immunology; D011181:Postnatal Care / Q000379:methods; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*; D015597:Pregnancy Complications, Parasitic / Q000276:immunology / Q000517:prevention & control; D011295:Prenatal Care / Q000379:methods; D014373:Tuberculin / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D014801:Vitamin A / Q000097:blood / Q000276:immunology* / Q000627:therapeutic use; D014802:Vitamin A Deficiency / Q000276:immunology*
chemical_list: D016207:Cytokines; D010835:Phytohemagglutinins; D014373:Tuberculin; D014409:Tumor Necrosis Factor-alpha; D014801:Vitamin A; D016753:Interleukin-10; D007371:Interferon-gamma