Medical case narrative
A 45-year-old man in a psychiatric hospital — pellagra, found on day 20
What happened
A 45-year-old man in China was admitted to a psychiatric hospital with a provisional diagnosis of "Psychosis Not Otherwise Specified." He also had dermatitis, and by day 3, diarrhoea — the classic pellagra triad was assembling in plain sight.
What it looked like
Psychosis first, because the psychiatric door was the one he came through. The skin and gut signs were there, waiting to be connected.
What the labs found
On day 20, pellagra — niacin (vitamin B3) deficiency — was confirmed, with a 24-hour urine N-methylnicotinamide level below 0.5 mg.
What changed
Recovery took about six months, on high-dose niacin plus vitamins B and C and glutamine; an antipsychotic (perphenazine) was also restarted at day 45. The honest headline is not "one vitamin cured him" — it is "a deficiency disease was found three weeks into a psychiatric admission, and full nutritional treatment, alongside psychiatric care, brought him back."
The test that told the story
Niacin status testing (urinary N-methylnicotinamide) — prompted by the dermatitis-diarrhoea-dementia triad.
Sources: Wang & Liang, Shanghai Archives of Psychiatry 2012 (PMC4198903).