Low vitamin D levels in COVID-19 patients may increase risk of long COVID

Istanbul: A recent study has linked low vitamin D levels with the increased risk of Long COVID, indicating individuals should have their vitamin D levels checked after COVID-19. The study was presented at the 25th European Congress of Endocrinology in Istanbul. 

Also known as post-COVID-19 syndrome, long COVID is a new condition in which the effects of COVID-19 last for more than 12 weeks after contracting the initial infection. Studies have shown that it affects 50-70% of patients previously hospitalised for COVID-19, yet very little is known about the condition. Low vitamin D levels are one risk factor for worse outcomes for hospitalised COVID-19 patients, such as intubation and mechanical ventilation or death. Still, its role in long COVID has not been adequately investigated.

For this study, supported by Abiogen Pharma SpA, researchers from the Vita-Salute San Raffaele University and IRCCS San Raffaele Hospital in Milan examined 100 patients aged 51-70 years, with and without long COVID. They measured their vitamin D levels when first admitted to the hospital for COVID-19 and six months after being discharged and found lower vitamin D levels in patients with long COVID than those without. This result was more evident in patients who experienced ‘brain fog’ symptoms, such as confusion, forgetfulness and poor concentration, at the six-month follow-up.

The researchers included patients without bone conditions and only those who went to hospital for COVID-19 without ending up in intensive care units (ICUs). They matched the two groups, with and without long COVID, regarding age, sex, pre-existing chronic diseases and COVID-19 severity. “Previous studies on the role of vitamin D in long COVID were not conclusive mainly due to many confounding factors,” said lead investigator Professor Andrea Giustina. “The highly-controlled nature of our study helps us better understand the role of vitamin D deficiency in long COVID and establish that there is likely a link between vitamin D deficiency and long COVID.”

While Professor Giustina acknowledges that larger studies are needed to confirm this link, he and his team are now focused on determining whether vitamin D supplements can reduce the risk of long COVID. “Our study shows that COVID-19 patients with low vitamin D levels are more likely to develop long COVID but it is not yet known whether vitamin D supplements could improve the symptoms or reduce this risk altogether.”

Reference:

Low levels of vitamin D linked to long COVID, European Society of Endocrinology, Meeting, European Congress of Endocrinology 2023.