Vitamin A supplementation increases ratios of proinflammatory to anti-inflammatory cytokine responses in pregnancy and lactation

Authors

  • S. E. Cox,

    Corresponding author
    1. Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine (LSHTM), London, UK,
    2. Department of Infectious and Tropical Diseases, LSHTM, London, UK, and
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  • P. Arthur,

    1. Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine (LSHTM), London, UK,
    2. Kintampo Health Research Centre, Ghana Health Service, Kintampo, Brong Ahafo Region, Ghana
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  • B. R. Kirkwood,

    1. Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine (LSHTM), London, UK,
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  • K. Yeboah-Antwi,

    1. Kintampo Health Research Centre, Ghana Health Service, Kintampo, Brong Ahafo Region, Ghana
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  • E. M. Riley

    1. Department of Infectious and Tropical Diseases, LSHTM, London, UK, and
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Dr Sharon E. Cox, Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
E-mail: sharon.cox@lshtm.ac.uk

Summary

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)-γ and tumour necrosis factor (TNF)-α. Mitogen-induced TNF-α 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-γ) 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.

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