Increase of serum vitamin D levels in the COVID-19 pandemic: Report of a Mexican reference clinical laboratory

Background

The COVID-19 pandemic prompted health professionals to look for prevention and treatment options to improve outcomes. Vitamin D3 (VitD) is a sun dependent, immunomodulatory hormone that was widely used approaching COVID-19 because of previous experience with other RTIs. Its use was recommended in clinical practice guidelines and mainstream media, motivating supplement consumption. This increased the demand for serum VitD determinations, as well as the progressive increase of serum VitD levels.

Objective

Study the change in mean VitD serum levels in the population of one reference clinical laboratory before and during pandemic years.

Methods

We analyzed 65,481 results (78% female, mean age of 53.47 (M = 55, IQR = 25)).

Results

The median Vitamin D level was higher in all seasons in the pandemic years compared to previous years: spring 24 ng/dL (IQR 13.7) vs 25.4 ng/dL (IQR 17), summer 23.5 ng/dL (IQR 13.4) vs 24.2 ng/dL (IQR 16.3), autumn 23.7 ng/dL (IQR 14.3) vs 27 ng/dL (IQR 18.7), winter 22.4 ng/dL (IQR 14.9) vs 23.4 ng/dL (IQR 17.8).

Conclusions

The increase in serum VitD during the pandemic years is probably due to the recommendations of its use in guidelines of clinical practice. Although up to date the CDC and NIH have deemed there is not enough information in favor or against VitD use, epidemiology studies should be done to observe the impact of widespread VitD use in COVID-19 and other illnesses.