Evaluating low and high vitamin D levels in Ecuadorian cities from 2018 to 2022: interrupted time series and a cross-sectional study.

The study's findings indicate a significant prevalence of 25(OH)D deficiency, underscoring the necessity for preventative measures. However, the increasing trend in high 25(OH)D levels is concerning, emphasising the importance of prudent vitamin D supplement prescriptions and public education against self-medication. For efficient resource allocation and targeting of those with higher risks, it may be advantageous to concentrate vitamin D testing on specific population groups.