Vitamin D deficiency and toxicity across 2018 to 2022 in several cities of Ecuador: interrupted time series and a cross-sectional study

Objectives to identify differences in mean vitamin D concentrations in samples obtained from a private laboratory in the city of Quito, and to explore their relationship with the pre-pandemic and pandemic periods spanning from 2018 to 2022. Design A combination of an interrupted time series design and a retrospective cross-sectional approach Setting and participants The study involved 9,285 participants who had their 25-hydroxyvitamin D (25(OH)D) levels tested at a well-known private laboratory in Quito, Ecuador, from 2018 to 2022. Primary and secondary outcome measures: The 25(OH)D levels were analyzed and assessed for correlations with both age and the year in which the measurements were taken. Results The mean 25-hydroxyvitamin D (25(OH)D) level was 27.53 ng/mL (± 14.11). Approximately 64.58% of participants had insufficient levels, below 20 ng/mL, and 0.62% showed potential harm from excess 25(OH)D, with levels over 100 ng/mL. The analysis indicated a significant monthly increase of 0.133 units in 25(OH)D levels (p=0.006). However, the period after March 2020, compared to before, saw a non-significant decrease of 1.605 units in mean 25(OH)D levels (p=0.477). Conclusions The study’s findings indicate a significant prevalence of 25-hydroxyvitamin D (25(OH)D) deficiency, underscoring the necessity for preventative measures. Nevertheless, the rise in cases of vitamin D toxicity is concerning, emphasizing the importance of prudent vitamin D supplement prescriptions and public education against self-medication. For efficient resource allocation and targeting those with higher risks, it may be advantageous to concentrate vitamin D testing on specific population groups.