Why are asthma rates among kids on the rise? Should we still take vitamin D supplements in the summer?

Dr. Elaine Chin answers your health questions

090716_pufferkidThere seem to be many more children with asthma than ever before. Are asthma rates on the rise, and if so, why?

North American asthma rates in children under the age of five have increased more than 160 per cent from 1980 to 1994. Children between five and 17 years of age missed 12.8 million school days due to asthma in 2003.

Some causes of asthma are known:

Genetics: Approximately 40 per cent of children who have asthmatic parents will develop asthma. The cause of this relationship is somewhat unclear but it may be due to genetic hypersensitivities to environmental chemicals and food.

Environmental: exposure to fumes, gases or dust, are responsible for 11 per cent of asthma cases worldwide.

Food and environmental allergies: About 70 per cent of asthmatics also have allergies. In our clinic, we perform antibody testing in clients with a history of asthma. What we are discovering is many of them have some form of food allergies especially to dairy, wheat and/or eggs. This is consistent with a U.S. study in 2007 that found 29 per cent of children who had a food allergy also had asthma.

As a Mom of a child with asthma, I am an advocate of doing whatever we can to prevent an asthma attack.

Keep a clean breathing environment – have a clean home, install a HEPA air filter, use hypoallergenic pillow cases and a mattress cover
Perform a food allergy test – blood IgG and IgE antibodies. (not a skin scratch test)

It has made a significant difference to my child’s life.

During the summer, we get a lot of sunlight. Should we still take vitamin D supplements?

The short answer is, usually not. Most of our body’s vitamin D is produced by our skin, using ultraviolet rays from the sun and not from food fortified with vitamin D.  For most of us, ensuring adequate production of vitamin D means exposing our faces and arms to moderately strong (midday) sunlight 10 to 15 minutes a day, three to four times a week. This can be easily achieved during the summer months. However, for many Canadians winter means reduced sun exposure. This leads to a reduction of vitamin D production and the depletion of this vitamin’s stored supplies in the body. A genetic problem – the inability of some individuals to manufacture good amounts of vitamin D – may compound this. The best way to decide how much vitamin D you require is to determine your vitamin D blood level. Storage vitamin D (Vit D – 25 OH) levels should be at least 75 nmol/L. Once you know the level you can decide if basking in the sun, eating fortified foods and/or taking a vitamin D supplement is right for you. Because vitamin D has such a strong impact on so many body organs and processes, vitamin D deficiency has been implicated as a causative factor in a variety of diseases. So it’s understandable why so many experts advocate the need to maintain high levels of vitamin D year round to help prevent diseases such as osteoporosis, cancer, depression, coronary disease, lupus, and multiple sclerosis.

Send your questions for Dr. Elaine Chin, chief medical officer of the Scienta Health Group, to

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