Vitamin D for Asthma

Dr. Harriott's comment:
Readers should pay particular attention to the preliminary nature of this report. Be aware that the data and conclusions in this paper were presented in conference and have not been published or subjected to peer review as of March, 2010. Also, causality has not been established in the relationship between Vitamin D and Asthma medication. In other words, we don't know from this information whether lower levels of vitamin D caused more severe asthma, or if use of steroid inhalers lowered vitamin D levels. In either case, supplementation to increase vitamin D for asthma sufferers appears prudent given its role in multiple areas of healthy immunological function. Lastly, please seek the advice of a qualified health professional as it pertains to supplementation dosage of Vitamin D, since this is a fat soluble vitamin and has the potential to accumulate to toxic levels with sustained excessive supplementation.
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From http://www.medpagetoday.com

By Crystal Phend, Senior Staff Writer, MedPage Today
Published: February 27, 2010
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
Action Points
Caution interested patients that the study could not determine causality or whether supplementing vitamin D would have any effect on asthma medication efficacy or symptom control.


Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
NEW ORLEANS -- Vitamin D may boost the anti-inflammatory efficacy of asthma medications but tends to be low in kids who need the drugs, researchers said.
Children taking oral or inhaled corticosteroids appeared to have lower vitamin D levels in a dose-related manner (P=0.001), Daniel A. Searing, MD, of National Jewish Health in Denver, and colleagues found.

In vitro experiments by the group showed that vitamin D improved anti-inflammatory markers MKP-1 and interleukin (IL)-10 and enhanced the activity of dexamethasone (Decadron, Dexpak) more than 10-fold.

"The implication is vitamin D could have a steroid-sparing effect in asthma," Searing said in an interview here at the American Academy of Allergy, Asthma & Immunology meeting where he presented the results.

However, whether vitamin D supplementation would translate to lower steroid doses or better asthma control remains to be seen, he cautioned.

Moreover, the researchers cautioned that the study could only suggest a correlation, not causality.

If there was causality involved, it's not clear which direction, Searing said -- whether steroid medications or simply more severe asthma reduced vitamin D levels in some way or whether low vitamin D might have caused more severe symptoms that necessitated treatment.

Nevertheless, treating vitamin D insufficiency may make sense given its links to a wide range of ill effects on health and the vitamin's important role in bone health, Searing said.

At his institution, "we tend to supplement patients if they are under 30 ng/mL," he told MedPage Today.

Vitamin D insufficiency rates affect an estimated 20% to 70% of American children, depending on the level at which insufficiency is defined.

In Searing's retrospective study, 47% of the 99 pediatric asthma patients seen at National Jewish Health had vitamin D levels below 30 ng/mL, considered insufficient.

Although this was similar to the prevalence in the overall pediatric population, lower vitamin D levels in the asthmatic children were associated with higher immunoglobulin E levels (P=0.01) and poorer lung function (P=0.33 to P=0.004).

Median vitamin D levels associated with medication use were significantly lower for children on:

Inhaled corticosteroids (29 versus 35 ng/mL, P=0.0475)
Oral corticosteroids (25 versus 32 ng/mL, P=0.02)
Long-acting beta agonists (25 versus 34 ng/mL, P=0.0007)
Higher total steroid doses (P=0.001 for trend)
When peripheral blood mononuclear cells from 11 of the children and four healthy controls were cultured, vitamin D significantly increased the levels of the anti-inflammatory marker MKP-1 (P<0.01 to P<0.001) and the anti-inflammatory cytokine IL-10 (P<0.05) with greater effects at a higher vitamin D dose.

"Whether or not that would correlate physiologically really cannot be inferred from our data," Searing warned in an interview.

But, he speculated, low vitamin D may have greater implications for the health of children with asthma than those who don't have it.

The study was supported in part by grants from the National Institutes of Health.

The researchers reported no conflicts of interest.


Primary source: American Academy of Allergy, Asthma & Immunology
Source reference:
Searing DA, et al "Vitamin D Levels in Children with Asthma, Atopic Dermatitis, and Food Allergy" AAAAI 2010; Abstract 176.




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