I don't know enough about citicoline to respond directly to your question but SAD lamps have helped me get through winter. Tanning salon also helps. I don't go enough to get an actual tan but the light therapy has an immediate noticeable positive effect.
Northern Light Technologies... https://www.amazon.com/dp/B003XDIPNA?ref=ppx_pop_mob_ap_share
Here's the one we have. It's highly rated, and not a table top one. A cheap one won't work unfortunately because they have to be able to put out a very strong amount of light 😕
I got this one: https://smile.amazon.com/gp/product/B003XDIPNA/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1. There are also more affordable desk versions, but I wanted to get a floor lamp so I could also point the light towards the ceiling and get better lighting in the room, in addition to the direct use. I do think it has helped for me. I only get relatively mild winter blues, but it definitely helps me wake up/feel more energy in the early morning.