Hypocalcemia in hospitalized patients with COVID-19: roles of hypovitaminosis D and functional hypoparathyroidism

Abstract

Introduction Despite the high prevalence of hypocalcemia in patients with COVID-19, very limited studies have been designed to evaluate etiologies of this disorder. This study was designed to evaluate the status of serum parameters involved in calcium metabolism in patients with COVID-19 and hypocalcemia. Materials and methods This cross-sectional study was conducted on 123 hospitalized patients with COVID-19. Serum concentrations of PTH, 25 (OH) D, magnesium, phosphate, and albumin were assessed and compared across three groups of moderate/severe hypocalcemia (serum total calcium < 8 mg/dl), mild hypocalcemia (8 mg/dl ≤ serum total calcium < 8.5 mg/dl) and normocalcemia (serum total calcium ≥ 8.5 mg/dl). Multivariate analyses were performed to evaluate the independent roles of serum parameters in hypocalcemia. Results In total, 65.9% of the patients had hypocalcemia. Vitamin D deficiency was found in 44.4% and 37.7% of moderate/severe and mild hypocalcemia cases, respectively, compared to 7.1% in the normal serum total calcium group ( P = 0.003). In multivariate analysis, vitamin D deficiency was independently associated with 6.2 times higher risk of hypocalcemia ( P = 0.001). Only a minority of patients with hypocalcemia had appropriately high PTH (15.1% and 14.3% in mild and moderate/severe hypocalcemia, respectively). Serum PTH was low/low-normal in 40.0% of patients with moderate/severe low-corrected calcium group. Magnesium deficiency was not associated with hypocalcemia in univariate and multivariate analysis. Conclusion Vitamin D deficiency plays a major role in hypocalcemia among hospitalized patients with COVID-19. Inappropriately low/low-normal serum PTH may be a contributing factor in this disorder.

Impaired Vitamin D Metabolism in Hospitalized COVID-19 Patients

“…The observed increase in circulating active vitamin D metabolite could be partly aimed at preventing hypocalcemia in COVID-19 patients with low total and free 25OH-D levels. Recent data on impaired compensatory PTH response in hypocalcemic patients with COVID-19, obtained by other research groups [ 60 , 61 ], support this hypothesis and may be due to negative feedback from 1,25(OH) 2 D 3 , although in our cohort, PTH levels were similar to the reference group.…”

Association between calcium and vitamin D in geriatric patients hospitalized for Covid-19: Results from the GERIA-COVID study

“…Hypothesis to explain our results could be the suppression of secondary hyperparathyroidism in the context of hypomagnesemia supported by the high prevalence of hypomagnesemia in COVID-19 (19). Hypomagnesemia suppresses secondary hyperparathyroidism in osteoporotic patients (20) but there is not strong evidence of the impact of hypomagnesemia on calcic metabolism in COVID-19 (12,13).…”

“…Hypocalcemia is frequently associated with COVID-19 (11,12); the mechanism of these imbalances in calcium metabolism is not fully understood. Furthermore, none of the studies conducted to investigate the relationship between COVID-19, 25(OH)D and hypocalcemia have focused on the older population (12,13). Paradoxically, the mortality rate of this disease in older patients is high and increases with age (14).…”

Current evidence on the impact of the COVID-19 pandemic on paediatric endocrine conditions

“…Calcium is recognized to play an important role in viral infections, and hypocalcemia has been reported in many cases of adult patients with covid-19 and requiring admission to hospital (68, 69), and has been related also with a higher mortality risk (70). Although vitamin D deficiency is one of the main causes of hypocalcaemia, inappropriate levels of parathyroid hormone (PTH) are a contributing factor (71). Although there are no reports in childhood, recently two case reports evidence that SARS-CoV-2 infection can cause primary hypoparathyroidism and decompensate previous primary hypoparathyroidism independent of vitamin D levels (72,73).…”