This video is about how listening to various Dr. Mercola interviews on Natural Health and Vitamin D Optimization led to my interest in the Immune System. www.drthomasbrewer.com www.facebook.com/drthomasbrewer Helpedimmune systemIMMUNITYiMovieImportanceMercolaOptimizationrealizevideoVITAMINvitamin immune systemvlogYouTube