68 percent got vitamin D above 40 ng by regular use of tanning bed
Chart from Grassroots Health

PDF is attached at the bottom of this page
See also Vitamin D Life
UVA decreased serum levels of vitamin D - RCT Oct 2012 - be sure that UV source has enough UVB
UVB added in classroom reduced cavities, increased height, increased academics. etc
Top UK soccer coach installed vitamin D booths in his club – Dec 2012
Interview with transcript concerning UVA, UVB, and health – Grant Dec 2012
Increase your vitamin D from the sun by wearing a tan-through instead of standard shirt
Allergic to the sun (Polymorphic light eruption) – you may need UVB or vitamin D
3 tanning sessions raised vitamin D levels about 4 nanograms for about 4 weeks – July 2016