I have read a lot of stuff about Vitamin D. Last year about this time, we started taking it in supplement form. Dr. Mercola says to take Vitamin D3. We did not get the colds or flu that went around last year. I am not sure this was the only factor, but I am sure it helped. Please watch this video.
This is the brand we took. We have done some research on different brands and are really happy with the Beeyoutiful line of products. You can click on the picture below to take you to their site. Their prices are good and shipping is lower than most places.