Thank you for sharing your question on the EmpowHER community.
Vitamin D home test are used to test your vitamin D blood levels. You can find test kits on Amazon, however there is a website (www.vitamindcouncil.org) that is devoted to the subject sharing information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health. They also boast about being the lowest cost wise in the US for vitamin D test kits.
Home Kit Info
I hope this helps.