The number of people diagnosed with coeliac disease in the UK has increased fourfold since 1990, new results show.

Research from the University of Nottingham, funded by charity Coeliac UK and CORE, has shown that the level of diagnosis has increased to 24%.

This was previously estimated to be between 10-15%, according to the National Institute of Health & Care Excellence (NICE).

The research also found that three-quarters of people with the disease remain undiagnosed.

Sarah Sleet, chief executive of Coeliac UK, said: “This latest research shows that nearly a quarter of people with coeliac disease have now been diagnosed and gives an up-to-date picture of the diagnosis levels across the UK.

“Of course, increasing numbers with a diagnosis is good news and will inevitably mean there will be an increased demand for gluten-free products in supermarkets. But the three-quarters undiagnosed is around 500,000 people – a shocking statistic that needs urgent action.”

Coeliac disease is an autoimmune disease caused by intolerance to gluten. Left untreated it may lead to infertility, osteoporosis and small bowel cancer. One in 100 people in the UK have coeliac disease, with the prevalence rising to one in 10 for close family members.

From 12-18 May 2014, Coeliac UK is running an awareness week urging supermarkets to improve the availability of gluten-free foods in their smaller stores.

The charity is asking people across the UK to tell them how many of the eight gluten-free staple items they can find. This includes: white bread, pasta, cereal, flour, cereal bars, rolls, crackers and other bread (brown or seeded).

According to the charity, 74% of members said that they had to visit more than one supermarket to complete their shopping.