What food supplement should we use during this epidemic time?

Here below the Mushroom products maybe help you in some factor:

Flammulina velutipes extract polysaccharide 30%; 
Lentinus edodes polysaccharide 30%; 
Ganoderma lucidum polysaccharide (fruity body) 30% polysaccharide powder
Ganoderma spore powder;
50% polysaccharide of Betula platyphylla  ;
Polysaccharide of Hericium ericium 50%, 30% ; 
30% polysaccharide of tricholoma platyphylla (fruiting body)  ;
Herinus erinus extract 10:1  ;
Grifola frondosa polysaccharide 10% fruitbody.

lion's mane mushroom extract powder

Beside:  You can also take some supplement like Vitamin C tablets.