Can I get the same pain benefits from sun exposure as from a vitamin D supplement?

Most likely yes, and possibly more benefit! Relatively few trials have been done on sun exposure and health because it’s harder to control someone’s total dose without keeping them confined in some way, but the limited evidence is telling. For example, a small pilot trial^[1] showed that UV-enriched tanning beds could help fibromyalgia pain. Although laying in a tanning bed doesn’t exactly equate to sun exposure, it does subject your skin to UV rays, And exposure to UV rays can have several non-vitamin D-related benefits^[2] that could help with pain, such as increased endorphin production and nitric oxide synthesis.