I visited Harvest Health Food Store a couple days ago to find out how the winter blahs can be helped naturally.  Their suggestion, for someone like me, and probably someone like you, who gets too little light in these winter months in West Michigan, is Vitamin D with magnesium.  For me, I went on a mega dosage for a couple months.  It did appear to help somewhat, but did not completely rid me of the blahs.  A couple other people here at the radio station did the same thing and felt like they experienced a lifting of the blahs.  It is a real thing and it's called Seasonal Affective Disorder also know as SAD or S.A.D. and occurs when our days get shorter and sunshine is lacking.