Scientists have found a link between lower-than-average levels of vitamin D and high numbers of COVID-19 cases and mortality rates across 20 European countries.

The research, led by Dr Lee Smith of Cambridgeshire and Essex-based Anglia Ruskin University (ARU) and Petre Cristian Ilie, lead urologist at Queen Elizabeth Hospital, King's Lynn, is published in the journal Aging Clinical and Experimental Research.

The highest average levels of vitamin D are found in northern Europe, due to the consumption of cod liver oil and vitamin D supplements, and possibly less sun avoidance than in southern Europe.

Dr Lee Smith, reader in physical activity and public health at ARU, said: "Vitamin D has been shown to protect against acute respiratory infections, and older adults, the group most deficient in vitamin D, are also the ones most seriously affected by Covid-19."