If you have been affected by any of the issues in this story, help and support is available via BBC Action Line.

An inquest heard that Georgina Owen, who had been studying geography at Swansea University, died at Addenbrooke’s Hospital on 21 September, two days after she had been found at her home address, together with a note.

Her death led to her parents, both healthcare professionals, to investigate the effects of B12 deficiency, and what they saw as gaps in awareness, testing and treatment, particularly around its psychiatric symptoms.

“This isn’t about veganism,” Julian Owen said.

“Many medicines we give patients in the modern era reduce your ability to absorb B12.

“A lot of people take omeprazole, a proton pump inhibitor, and that stops the acid stomach and you can’t absorb iron or B12 so well.

“We have a population who are at risk of micronutrient deficiency and B12 is the highlighted one here, but there is a major issue nationally about nutritional status.

“I suppose the bigger issue is to bring nutrition back onto people’s awareness.”