Research presented at the 25th European Congress of Endocrinology in Istanbul suggests individuals with low levels of vitamin D have an increased risk of long COVID. The findings suggest that individuals should have their vitamin D levels checked after COVID-19.
Long COVID, also referred to as post-COVID-19 syndrome, is a relatively recent health condition characterized by COVID-19 symptoms persisting for over 12 weeks after the initial infection. Studies have shown that this condition impacts between 50-70% of those who have been hospitalized due to COVID-19. Despite its prevalence, our understanding of long COVID remains limited.
One risk factor for worse outcomes for hospitalized COVID-19 patients, such as intubation and mechanical ventilation or death, is low vitamin D levels, but 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 hospital for COVID-19 and six months after being discharged, and found lower vitamin D levels in patients with long COVID compared to 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 any bone conditions and only those who went to hospital for COVID-19, without ending up in the intensive care units (ICUs). They matched the two groups, with and without long COVID, in terms of 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 finding out 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 Vitamin D Levels Are Associated With Long COVID Syndrome in COVID-19 Survivor” by Luigi di Filippo, Stefano Frara, Fabrizio Nannipieri, Alice Cotellessa, Massimo Locatelli, Patrizia Rovere Querini and Andrea Giustina, 13 April 2023, The Journal of Clinical Endocrinology & Metabolism.