Vitamin D Status and the Host Resistance to Infections: What It Is Currently (Not) Understood

Clin Ther. 2017 May;39(5):930-945. doi: 10.1016/j.clinthera.2017.04.004. Epub 2017 Apr 28.

Abstract

Purpose: Vitamin D is increasingly thought to play a role in regulating immunity. This comprehensive review updates the current understanding regarding ways in which we believe that vitamin D regulates responsiveness of the immune system and how serum status modulates the host defense against pathogens.

Methods: The literature was searched by using PubMed and Scopus with the following key words: vitamin D, immunity, innate and adaptive immunity, infectious disease, and vaccine response.

Findings: Vitamin D deficiency remains a major public health concern worldwide. The overall body of evidence confirms that vitamin D plays an important role in modulating the immune response to infections. Epidemiologic studies suggest a clear association between vitamin D deficiency and susceptibility to various pathogens. However, translation of vitamin D use into the clinic as a means of controlling infections is fraught with methodologic and epidemiologic challenges. The recent discovery of alternative activation pathways, different active forms of vitamin D, and possible interaction with non-vitamin D receptors provide further complications to an already complex interaction between vitamin D and the immune system. Moreover, it has become apparent that the individual responsiveness to supplementation is more dynamic than presumed from the static assessment of 25-hydroxy vitamin D status. Furthermore, the epigenetic response at the level of the individual to environmental changes and lifestyle or health conditions provides greater variation than those resulting from vitamin D receptor polymorphisms.

Implications: To understand the future of vitamin D with respect to clinical applications in the prevention and better control of infectious diseases, it is necessary to determine all aspects of vitamin D metabolism, as well as the mechanisms by which active forms interact with the immune system globally. For the most part, we are unable to identify tissue-specific applications of supplementation except for those subjects at high risk of osteomalacia and osteoporosis.

Keywords: immune response; immunity; infections; vaccine; vitamin D; vitamin D status; vitamin D supplementation.

Publication types

  • Review

MeSH terms

  • Animals
  • Communicable Diseases* / blood
  • Communicable Diseases* / drug therapy
  • Communicable Diseases* / immunology
  • Dietary Supplements
  • Disease Resistance / immunology*
  • Humans
  • Immunologic Factors* / blood
  • Immunologic Factors* / immunology
  • Immunologic Factors* / therapeutic use
  • Vaccines / therapeutic use
  • Vitamin D* / blood
  • Vitamin D* / immunology
  • Vitamin D* / therapeutic use
  • Vitamins* / blood
  • Vitamins* / immunology
  • Vitamins* / therapeutic use

Substances

  • Immunologic Factors
  • Vaccines
  • Vitamins
  • Vitamin D