This study demonstrated that inadequate dietary intake of vitamin E (VE) led to an increase in anxiety-like behavior in rats. Notably, this behavioral change appeared before the onset of physical symptoms of VE deficiency, suggesting that even individuals with subclinical or latent VE deficiency—those who do not yet exhibit overt deficiency symptoms—may still be at risk for compromised mental health. Furthermore, anxiety-like behavior induced by VE deficiency was exacerbated under the stress of social isolation. In adrenalectomized rats, neither an increase in blood corticosterone levels nor anxiety-like behavior was observed following VE deficiency, indicating that elevated corticosterone, a stress hormone, may play a key role in mediating these behavioral changes. These findings may offer insights into the prevention and treatment of stress-related mental health disorders in modern society, where such conditions are increasingly prevalent.