Both my DC have flakey nails, just at the top once they get a little longer than very short, makes them prone to picking at them. They both eat a mainly vegetarian diet with some not enough fish. DS eats loads of different veg but DD is very fussy and restricted and drinks her own body weight in almond milk. They both eat plenty of fruit and drink water, rarely anything else. They eat cheese and eggs, and take a general kids multivitamin most mornings. They're otherwise healthy except Dd is prone to occasional excema and they both have fairly dry skin because of where we live
But he nail thing bothers me and makes me wonder if they're missing some vital nutrients somewhere, particularly Dd