Vitamin D in asthma - summary from 2011 CSACI meeting

This summary was compiled from tweets posted by Dr. Stuart Carr @allergydoc4kidz, the president of the Canadian Society of Allergy and Clinical Immunology (CSACI). The tweets were labeled #CSACI and they reached more than 10,000 people. I would strongly encourage you to post updates on Twitter from the CME conferences that you are planning to attend in the future.

Alia Bazzy-Asaad spoke on vitamin D, asthma and allergy:

Vitamin D controls more than 500 genes, there is an enormous range of function. Vitamin D is a steroid hormone and a component of a complex endocrine pathway sometimes called 'vitamin D endocrine system' (Medscape, 2012).

Several studies support a protective role for vitamin D in asthma, but there a few negative studies that did not show a difference. Vitamin D levels correlate with lung function (NHANES III). NHANES data suggest lower vitamin D levels now compared to 20 years ago.

There was an Inverse relationship between vitamin D levels and serum IgE, eosinophils, and odds of hospitalization for asthma in Costa Rican children.

Vitamin D levels correlate with asthma control and risk of EIB in Italian children.

The risk of recurrent wheeze by age 3 was decreased with higher maternal intake of vitamin D (greater than 400 IU per day). However, a follow up study showed that cord blood levels of vitamin D correlate with the probability of wheeze over the first 3 years of life, but not asthma diagnosis by age 5.

There are fewer URTI with with higher vitamin D levels.

There is an Inverse relation between house dust mite (HDM) IgE and vitamin D levels seasonally in Australians.

Low vitamin D level at age 6 in males was associated with increased risk of asthma age 14.

Disclaimer: The text was edited, modified, and added to by me. I was invited to speak on the topic of social media use by the allergists during the 2011 CSACI meeting.

Editor's notes:

Despite the ability to get vitamin D from food and the sun, an estimated 40%-75% of people are deficient. The sun is not a reliable source.

Vitamin D is naturally present in few foods. Since 1930, virtually all cow's milk in the U.S. has been voluntarily fortified with 100 IU of vitamin D per cup.

The IOM committee set a level of 4,000 IU as the ‘tolerable upper limit' or the maximum amount of vitamin D that is safe to consume daily. In July 2011, the Endocrine Society Practice Guidelines published recommendations for the evaluation, treatment, and prevention of vitamin D recommending an upper limit of 10,000 IU/day.

Your health care provider can check your vitamin D blood level with a simple blood test.

A minimum vitamin D blood level of 30 nanograms/ml (25(OH)D) is an acceptable level at this time. New studies are ongoing.

References:

Are You Getting Enough Vitamin D? WebMD.