There are a fair number of clinics that will do blood tests for you. This is the first one that came up on DDG: https://www.everlywell.com/products/vitamin-d-t

There are a fair number of clinics that will do blood tests for you. This is the first one that came up on DDG: https://www.everlywell.com/products/vitamin-d-test/ https://www.everlywell.com/products/vitamin-d-test/ $49 but you have to prick your finger for the blood they need.