I also find it odd that you've included dairy in this post. Over-all, dairy has many more negative effects than positive. Also, recent science shows that Vitamin D does not help fight or prevent a cold. http://healthland.time.com/2012/10/03/trying-to-avoid-a-cold-skip-the-vitamin-d-supplements/
This article is about immunity boosting during the cold season not what to do WHEN you have a cold. But since you challenge the link between dairy and colds I have inseted a webink from the NIH regarding drinking milk when you have a cold. http://www.ncbi.nlm.nih.gov/pubmed/2154152
If you choose to not have dairy be a source of nutrition in your daily diet that is a personal preference. Thank you for this very informative article Yoga Journal.
Dairy has more negative effects when it comes to colds than positive, it causes mucus and therefore is a really good thing to avoid when you are getting a cold. Vitamin D is added to milk so it can be gotten anywhere, fortified cereals or fortified non-dairy milks such as rice , soy, hemp or almond without the mucus causing side effects.Please do your homework next time.
Your recommendation to drink milk, to build immunity, is absurd.