Vitamin A status is associated with T-cell responses in Bangladeshi men

Shaikh M. Ahmad, Marjorie J. Haskell, Rubhana Raqib, Charles B. Stephensen

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

Recommendations for vitamin A intake are based on maintaining liver stores of ≥0.070μmol/g, which is sufficient to maintain normal vision. We propose that higher levels may be required to maintain normal immune function. To test this hypothesis, we conducted an 8-week residential study among thirty-six healthy Bangladeshi men with low vitamin A stores. Subjects were randomised to receive vitamin A (240mg in four doses) or placebo during study weeks 2 and 3. Vitamin A stores were estimated by isotopic dilution at week 8. Total T-cells, the naive T-cells:memory T-cells ratio and mitogen-induced lymphocyte proliferation were positively and significantly correlated with vitamin A stores (P<0.05). Mitogen-stimulated IL-2, IL-4 and TNFα increased significantly (P<0.05) in the vitamin A but not placebo group after supplementation, while IL-10 production was significantly and negatively correlated with vitamin A stores (P<0.05). Segmented linear regression analysis revealed that naive T-cell counts and T-cell blastogenesis were positively associated with vitamin A stores above but not below 0.070μmol/g liver. These data show that increasing vitamin A stores above the level that maintains normal vision enhances some measures of T-cell-mediated immunity, suggesting a difference in requirements for maintaining vision and immune function.

Original languageEnglish (US)
Pages (from-to)797-802
Number of pages6
JournalBritish Journal of Nutrition
Volume102
Issue number6
DOIs
StatePublished - Sep 2009

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Keywords

  • [H]retinol dilution
  • RDA
  • T helper type 1 and 2 cytokines
  • T-cell phenotypes
  • Vitamin A
  • Vitamin A stores

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics
  • Medicine(all)

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