Thursday, January 20, 2011

Vitamin D, the immune system and asthma

In reading other eczema blogs, I stumbled upon a paper from which I will try to accurately summarize:
Vitamin D, the immune system and asthma
which is dated November 2009 and written by Nancy E Lange, MD, MPH, Augusto Litonjua, MD, MPH, Catherine M Hawrylowicz, PhD, and Scott Weiss, MD from Brigham & Women's Hospital. I'm not familiar with the authors or any of their previous work, but I did find this interesting.  Here are a few excerpts:
This article will summarize some of the emerging evidence on the complex role of vitamin D in the immune system relevant to asthma, and provide an overview of investigations thus far linking vitamin D and asthma.
Key issues

  • Recent evidence points to vitamin D as an essential immune system regulator.
  • Vitamin D deficiency and insufficiency are widespread, regardless of latitude.
  • Low vitamin D levels have been linked with many immune-mediated diseases and cancers.
  • Basic science and animal models demonstrate the multiplicative effects of vitamin D on cells of the immune system and cytokine profiles.
  • Genetic and epidemiologic studies have shown an association between asthma and vitamin D.
  • The rising prevalence of asthma may be linked to vitamin D deficiency.
  • Further investigation is needed to fully understand the role of vitamin D in the development of allergy and asthma.

Extraskeletal effects of vitamin D
In humans, vitamin D is obtained through ultraviolet B exposure, diet and supplement intake. It is converted to 25-hydroxyvitamin D3 by the liver. Circulating 25-hydroxyvitamin D3 is converted to the active form, 1,25-dihydroxyvitamin D3, in a variety of sites including the kidney and cells of the immune system. Experimental evidence suggests an effect of 1,25-dihydroxyvitamin D3 on multiple different processes and cell types. In the immune system it leads to a decrease in the Th1 response, thought to be the mechanism involved in the association between low vitamin D levels and a variety of autoimmune diseases. It modulates the Th2 response affecting cytokines such as IL-4, IL-5 and IL-13. This is one possible link between vitamin D and allergy/asthma. It has been shown to upregulate T-regulatory cells, leading to an increase in the synthesis of the anti-inflammatory cytokine IL-10. In macrophages, vitamin D upregulates synthesis of the antimicrobial peptide cathelicidin, which may enhance the ability to fight infections. In airway smooth muscle cells, it has been shown to modulate chemokine release. Vitamin D may play a role in fetal lung development and in the differentiation of type II pneumocytes and surfactant secretion. Vitamin D has also been associated with a lower incidence of and mortality from a variety of cancers.
The paper concludes with "The role of vitamin D in the pathogenesis of immune-mediated diseases such as asthma is only beginning to be understood. Several ongoing or planned human clinical trials are aimed at clarifying this link in the next 5 years. . . The elucidation of the precise roles of vitamin D in the immune system and in the pathogenesis of multiple diseases has the potential to have profound effects on our ability to prevent and treat these disorders."

I hope my summary was an accurate account, and no disservice was done.


  1. My son has had horrible asthma since birth. With alot of biomedical work the asthma left for many years.

    After his wood NAET treatment last week, he has had a cold with asthma. :( I am definately going to give hime vitamin D tomorrow!


  2. Sorry to hear about your son's asthma returning. I thought I saw you post that somewhere and it struck me funny because I knew he had been asthma free for quite some time. In my NAET experience, I would highly suspect the NAET treatment as a possible trigger. We have seen asthma after a handful of treatments in my son. My husband, who is also undergoing NAET, frequently gets feverish and almost always wiped out after a treatment. But like clockwork, he'd fine after 25 hours. Hope your son feels better fast!

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