This is a known fact and many studies have been done,
Fears, stress, and anxiety cause damage and weaken the immune system.
And a weak immune system exposes us to a virus infection.
Vitamins, sun, and all other alternative ways to strengthen the immune system,
Are nice but NOT effective.
Vitamins do not solve fears or stresses.
Fear and stress are emotional problems and they'll damage the immune system even if we consume vitamins.