@timeghost Welcome to Mayo Clinic Connect. I am curious if your dr ran any labtest to see it you indeed show a deficiency in Vit D? Some people have a difficult time absorbing Vit D, like my sister. I typically have to take additional Vit D supplements.

Sun sensitivity can be the result of side effects to a medication, hereditary tendencies [do any relatives have the same issues?], or an indication of an autoimmune condition, Here is an article from Mayo Clinic that you might find helpful. https://www.mayoclinic.org/diseases-conditions/sun-allergy/symptoms-causes/syc-20378077

For me, the sun sensitivity raised its head in 1988, and got worse. We eventually found I was dealing with Systemic Lupus, after going through a lot of tests including a skin biopsy. Will your dr consider sending you to a rheumatologist for some detailed answers?

Please come back and let me know what you find out, okay?
Ginger