New Delhi, May 13 : Low levels of vitamin D have now been linked to increase the long Covid risk, researchers report. The findings suggest that individuals should have their vitamin D levels checked after Covid infection. "The 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," said lead investigator professor Andrea Giustina from Vita-Salute San Raffaele University in Milan, Italy. Long Covid is a 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 per cent of patients previously hospitalised for Covid-19, yet very little is known about the condition. For this study, published in The Journal of Clinical Endocrinology & Metabolism and 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). "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," said Giustina. /IANS