Is COVID-19 lockdown associated with vitamin D deficiency?

All vitamin D tests carried out for outpatients aged 18 years or older during the last 3 years at an Italian University Hospital was reviewed. The serum vitamin D concentrations measured since the Italian coronavirus diseases 2019 (COVID-19) lockdown to present did not significantly differ from the previous 2 years (78 vs. 77 nmol/l; P = 0.277), whilst the prevalence of vitamin D deficiency was found to be even marginally lower in 2020 (16.0% vs. 17.9%; P = 0.003). These results suggest that vitamin D deficiency in our province has not increased during the Italian COVID-19 outbreak or in correspondence with the nationwide lockdown.