My daughter was diagnosed with b-6 deficiency, I was wondering what lasting effects this would have developmentally?

VIT B6 DEFICIENCY. Sx include peripheral neuropathy, seizures not controlled with anticonvulsants, mental retardation and anemia.
See below: Vitamin b6 (pyridoxine) is required for the synthesis of the neurotransmitters serotonin and norepinephrine and for myelin formation. Deficiency in adults principally affects the peripheral nerves, skin, mucous membranes, and the circulatory (blood cell) system. In children, the central nervous system (CNS) is also affected. It's extremely rare to have a deficiency of b6!