Harvard researchers have shown that decreasing rates of vitamin D could have been a part of the increasing rates of asthma and allergies. Rates of allergy and asthma has directly increased in parallel with the decrease in vitamin D levels in the general population; the connection is so significant that it may actually be a cause behind these two chronic conditions.

This research was actually published in 2007. Why aren’t we hearing more about it?

Researchers actually looked at changes in the North American lifestyle in the past 50 years. We’ve gone from a culture where walking was common to a culture where even kids are shuttled everywhere by car. With the advent of air conditioning, less time is spent outdoors in the prime time periods where sun on our skin means vitamin D to our bodies.

Not only do we spend less time outdoors, we spend more time protecting our skin from the sun. Sunblock is now commonly recommended for everyone and for every outdoor exposure. This results in even greater deficiency because we aren’t making vitamin D when the sun shines.

It’s not just your vitamin D intake that makes a difference for you. If your mother was deficient in vitamin D while you were in the womb, your chance of asthma and allergies are increased. It’s possible that low maternal vitamin D affects the immune system and lung development, predisposing the child to both asthma and allergy.

This is easy and inexpensive to fix however; just buy a vitamin D supplement and take at least 3,000 units if you are an adult. If you are pregnant, the recommendation is now 4,000. In our household, my preschooler gets 1,000 units daily and my middle-school aged child gets 2,000 units.

It works for more than just allergies: my children had the best winter ever, despite both being in school. We only had a couple of mild colds.