Does vitamin d deficiency affect the efficacy of the covid-19 vaccine or cause it not to work?

While vitamin D effects on immunity in general remain controversial, deficiency, specifically if treated, should not interfere significantly with acquired immunity against COVID. Supplementing your vitamin D as recommended would be best, getting the vaccine will give you the best chance to be protected when and if needed.

There has been not good work in this area. It might depend on the cause and degree of the Vit deficient discuss why the dr who knows you if you are concerned about ourself.