Hypomagnesemia and 25-hydroxyvitamin D deficiency in patients with long COVID.

Clinical manifestations related to hypomagnesemia and/or deficiency of vitamin D are frequent in patients with an extended course of coronavirus disease-2019 (long COVID). To evaluate hypomagnesemia and hydroxyvitamin D deficiency in patients with long COVID. A total of 125 adults with a diagnosis of long COVID were enrolled in a cross-sectional study. Participants were allocated into a risk (hypomagnesemia and hydroxyvitamin D deficiency) or control (serum magnesium and hydroxyvitamin D within normal ranges) group. Hypomagnesemia and 25-hydroxyvitamin D deficiency were defined based on serum level ≤1.8 mg/dL and <30 ng/mL, respectively. The number of clinical manifestations of long COVID were significantly higher in the risk compared to the control group. Fatigue, memory loss, attention disorders, joint pain, anxiety, sleep disorders, myalgia, and depression, all of which are related to hypomagnesemia and/or 25-hydroxyvitamin D deficiency, were among the 10 most frequent manifestations in the risk group. The adjusted odds ratio for the association between hypomagnesemia and hydroxyvitamin D deficiency during long COVID was 3.1; 95% CI 2.3-12.4, p=0.005. Our results show that patients suffering with long COVID had a deficiency in magnesium and 25-hydroxyvitamin D which correlated with the number of associated clinical manifestations.