I use a powder multi vitamin called "Soluvet" for my coclatoo- it has helped him lot-he has beak and feather disease- his feathers have grown (not to look like a normal cockatoo- but he has more feathers now than when i got him!!)

I ran out for about 3 weeks, and I saw the difference in him- he started to feel horrible- bought it as soon as I could, and he picked up within a couple of days!!

Also, infants (humans) multivitamin syrup is said to be good.

The Vixen