An Association of Serum Vitamin D Concentrations < 40 nmol/L With Acute Respiratory Tract Infection in Young Finnish Men

Am J Clin Nutr. 2007 Sep;86(3):714-7. doi: 10.1093/ajcn/86.3.714.

Abstract

Background: The effects of vitamin D in regulating bone mineralization are well documented. The action of vitamin D as a key link between Toll-like receptor activation and antibacterial responses in innate immunity has recently been shown. The data suggest that differences in the ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.

Objective: We aimed to explore whether an association exists between vitamin D insufficiency and acute respiratory tract infection in young Finnish men.

Design: Young Finnish men (n = 800) serving on a military base in Finland were enrolled for this study. Their serum 25-hydroxyvitamin [25(OH)D] concentrations were measured in July 2002. They were followed for 6 mo, and the number of days of absence from duty due to respiratory infection were counted.

Results: The mean (+/- SD) serum 25(OH)D concentrations were 80.2 +/- 29.3 nmol/L (n = 756). Subjects with serum 25(OH)D concentrations < 40 nmol/L (n = 24) had significantly (P = 0.004) more days of absence from duty due to respiratory infection (median: 4; quartile 1-quartile 3: 2-6) than did control subjects (2; 0-4; n = 628; incidence rate ratio 1.63; 95% CI: 1.15, 2.24). We found a significant (P = 0.004) association between serum 25(OH)D concentrations and the amount of physical exercise before induction into military service. We also found significantly (P < 0.001) lower serum 25(OH)D concentrations in subjects who smoked (72.8 +/- 26.6 nmol/L; n = 192) than in control subjects (82.9 +/- 29.7 nmol/L; n = 537).

Conclusion: Clinical trials of vitamin D supplementation are needed to investigate whether it enhances immunity to microbial infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adult
  • Analysis of Variance
  • Disease Susceptibility
  • Exercise / physiology
  • Finland / epidemiology
  • Humans
  • Incidence
  • Male
  • Military Personnel
  • Odds Ratio
  • Respiratory Tract Infections / blood*
  • Respiratory Tract Infections / epidemiology*
  • Respiratory Tract Infections / prevention & control
  • Smoking / blood
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood*
  • Vitamin D / therapeutic use
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / epidemiology*
  • Vitamin D Deficiency / prevention & control

Substances

  • Vitamin D
  • 25-hydroxyvitamin D