Vitamin D supplementation and hospitalization for infection in older adults: A post-hoc analysis of data from the Australian D-Health Trial

Hai Pham, Mary Waterhouse, Catherine Baxter, Briony Duarte Romero, Donald Sa McLeod, Bruce K. Armstrong, Peter R. Ebeling, Dallas R. English, Gunter Hartel, Rachel L. O'Connell, Jolieke C. van der Pols, Alison J. Venn, Penelope M. Webb, David C. Whiteman, Rachel E. Neale

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Abstract

BACKGROUND: Evidence suggests that vitamin D influences the immune system. Recent studies indicate that vitamin D supplementation may reduce the severity of infections, but this has not been confirmed. OBJECTIVES: The objective of this study was to assess the effect of vitamin D supplementation on hospitalization for infection. METHODS: The D-Health Trial was a randomized, double-blind, placebo-controlled trial of monthly 60,000 international units of vitamin D3 for 5 y among 21,315 Australians aged 60-84 y. Hospitalization for infection, ascertained through linkage with hospital admitted patient data, is a tertiary outcome of the trial. The primary outcome for this post-hoc analysis was hospitalization for any infection. Secondary outcomes were extended hospitalization for infection (length of stay >3 d and >6 d) and hospitalization for respiratory tract, skin, and gastrointestinal infections. We used negative binomial regression to estimate the effect of vitamin D supplementation on outcomes. RESULTS: Participants (46% women, mean age: 69 y), were followed up for a median of 5 y. Vitamin D supplementation had little or no effect on the incidence of hospitalization for any infection [incidence rate ratio (IRR): 0.95; 95% CI: 0.86, 1.05], respiratory tract (IRR: 0.93; 95% CI: 0.81, 1.08), skin (IRR: 0.95; 95% CI: 0.76, 1.20), gastrointestinal infections (IRR: 1.03; 95% CI: 0.84, 1.26), or hospitalizations lasting >3 d (IRR: 0.94; 95% CI: 0.81, 1.09), with all CIs consistent with a null finding. People supplemented with vitamin D had fewer hospitalizations lasting >6 d (IRR: 0.80; 95% CI: 0.65, 0.99). CONCLUSIONS: We did not find a protective effect of vitamin D on hospitalization for infection, but it reduced the number of extended hospitalizations. In populations where few people are vitamin D deficient, the effect of population-wide supplementation is likely to be small, but these findings support previous studies suggesting that vitamin D plays a role in infectious disease. The D-Health Trial is registered at the Australian New Zealand Clinical Trials Registry as ACTRN12613000743763.

Original languageEnglish
Pages (from-to)350-356
Number of pages7
JournalThe American Journal of Clinical Nutrition
Volume117
Issue number2
DOIs
Publication statusPublished - 1 Feb 2023

Keywords

  • gastrointestinal infection
  • hospitalization
  • infection
  • randomized controlled trial
  • respiratory tract infection
  • skin infection
  • vitamin D supplementation

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