Vitamin d boost may help psoriasis cream work better

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18 and older * Mild to severe plaque psoriasis (2% or greater Body Surface Area; Psoriasis Area and Severity Score of 2 or greater; Investigator Grade Assessment of mild-severe) Exclusion Criteria: * Currently taking medication that alters the normal ion balance of low-dose in blood. * No calcium supplements 1 month prior to baseline (not including multivitamins). * Unstable or uncontrolled illness, including but not limited to cerebro-cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematologic, neurologic or psychiatric disease at screening. * Abnormal laboratory values at screening, that in the opinion of the investigator, would potentially affect patient safety or data integrity. * Not on systemic non-biologic therapy (including, but not limited to, oral psoralen plus ultraviolet A \[photochemotherapy (PUVA)\] light therapy; cyclosporine; corticosteroids; methotrexate; oral retinoids; apremilast; tofacitinib; mycophenolate mofetil; thioguanine; hydroxyurea; sirolimus; tacrolimus; azathioprine; leflunomide; fumaric acid derivatives; or 1, 25 dihydroxy vitamin D3 and analogues) within 28 days prior to baseline. * No phototherapy (including either oral and topical PUVA light therapy, ultraviolet B, excimer laser, or self-treatment with tanning beds or therapeutic sunbathing) within 28 days prior to baseline. * No topical treatment (including, but not limited to, corticosteroids \[upper mid strength or lower potency topical steroids are permitted on the intertriginous areas and face\], crisaborole, anthralin, calcipotriene, topical vitamin D derivatives, retinoids, tazarotene, pimecrolimus, tacrolimus, emollients and other nonprescription topical products containing urea, \>3% salicylic acid, alpha- or beta-hydroxyl acids, or medicated shampoos \[for example those that contain \>3% salicylic acid, corticosteroids, coal tar, or vitamin D3 analogues\]) within 14 days prior to baseline. * No biologic agents within 8 weeks or three half-lives, whichever is greater prior to baseline. * History of renal impairment. * History of renal stones. * History of parathyroid abnormalities * Osteoporosis * History of severe arthritis * Ongoing use of tanning bed or other UV device or excessive sunlight * Unable to understand/complete informed consent.