Natural/full spectrum light box: http://www.verilux.com/light-therapy-lamps/winter-blues/
As has been mentioned; Vit D3, 10k units/daily; multivitamin w/iron; CoQ10 or idebenone; ALA; ALCAR; astaxanthin. Primarily to recycle glutathione.
St John's Wort and SAM-e for depression.