Safe UV lamps for the vitamin D deficient?

Every time I spend 20 minutes in the sun without sunscreen (after which I put on sunscreen), I notice immediate changes in my mood, energy level, alertness, mental acuity, focus and ability to sleep; I also simply think my skin looks better and healthier. I also know that I am vitamin D deficient, but even after 6 months of taking 5,000 IU vitamin D supplement pills once a day, I still only notice the above effects after time spent in the sun. I read “The Vitamin D Solution” which confirmed my theory that 20 minutes of sun exposure 3 times a week is necessary for production of the “vitamin D” hormone. However, what is one to do in the winter, or if you live in a northern, gray city, such as Vancouver, Canada? It is summer here but extremely gray and cloudy, and in the winter, if you work in an office building, it’s nearly impossible to get sun exposure. Most commercial tanning booths emit 95% UVA rays, which I do not believe are as effective at stimulating vitamin D hormone production as UVB. I have also purchased a “blue light” lamp which is believed to activate certain retinal photoreceptors, thereby decreasing the effects of SAD (seasonal affective disorder), but still, this is not nearly as effective as 20 minutes in the sun. The only other solution would be to purchase a UVB sun lamp (such as Sperti’s Vitamin D/UV-F lamp—but I cannot seem to find any research or user reviews on the safety of such lamps. Could anyone advise? Short of moving to So. Cal., I really feel stuck. Am I better off waiting 5 years until these lamps have been more sufficiently studied and calibrated?