Dr. Kathryn Boling discusses how vitamin D might help protect your immune system against COVID-19. Learn more at Baltimore MDBolingCoronavirusCOVID-19COVID19Dr. Kathryn Bolingimmune systemIMMUNITYinternal medicineKathrynMercyMercy HospitalMercy Medical CenterOfferprimary careProtectionvideoVITAMINvitamin COVID-19Vitamin DvlogYouTubeRelated Posts COVID’s New Variant Is Spreading Faster Than Expected April 18, 2026 COVID’s New Variant Is Spreading Faster Than Expected April 16, 2026 These Aren’t Just Hormone Problems April 16, 2026 New COVID Variant ‘Cicada’ Spreading Across U.S. | Seniors at Highest Risk April 15, 2026 Persistent immune activation and MS explosion #diseaseprevention April 13, 2026 Cicada COVID Variant Spreading in U.S. | What Doctors Want You to Know Now April 12, 2026