Prompt how to define or determine a hypovitaminosis And, and shortage of vitamins of group B, at...

[Andrey]

Prompt how to define or determine a hypovitaminosis And, and shortage of vitamins of group B, I am am hurted with eyes, the ophthalmologist has defined or determined a syndrome of a dry eye which can develop iz-for a hypovitaminosis And how these analyses are called, on shortage of vitamins?

[Gorshkov D.J.]

Hello, address in conference of "research".