Accuring evidence suggests incomplete nutrition may be a risk factor.
A trio of common nutrients may hold the key to better immune responses to all threats, including COVID 19.
Vit C ample dietary sources, but not well suited for the higher doses needed
Vit D, limited dietary sources and definitely not enough to equal 5000 IU in a tiny capsuel.
Zinc in the chelate form is far more biologically available than Zinc oxide