Vitamin D Supplementation During COVID-19 Lockdown and After 20 Months: Follow-Up Study on Slovenian Women Aged Between 44 and 66.

Vitamin D supplementation increased 7-fold compared to pre-pandemic levels and remained at a high level after 20 months. However, a significant number of participants discontinued supplementation, and only one-fifth were taking vitamin D throughout the entire year. Supplementation is effective for vitamin D deficiency prevention only at the individual level, however due to low compliance it should not be the only strategy for preventing vitamin D deficiency in the population.