When it comes to health, I would not trust Google as far as I could through them.
'via Blog this'
Google Flu Trends will supplement crowdsourced approach with CDC data | mobihealthnews:
On a positive note, notice the graph at the top that shows flu season. Not that people in America get colds and the "Flu" when sun light (Vitamin D) goes down and cold weather goes up. If memory serves me their is no flu season in Africa near the equator. The moral of the story is take your vitamin D in the winter as a cold prophylactic. I (an African American) go from 10,000 in the summer to 15,000 iu's in the winter. I live in the New York City area. This keeps my blood Vitamin D level at 80 to 90 ng ml.
The key hear is that vitamin D dosage if different for every human being depending on melanin content and other factors. You need to find what dose produces your target blood levels. By the way I have not had a cold to speak of in years.