[Chronic vitamin A poisoning with musculoskeletal symptoms and morphological changes of the liver: a case report]

The case of a 69-year-old woman with a chronic vitamin A intoxication syndrome after self-administration of vitamin A is presented. The clinical picture included musculoskeletal disorders, headache and hepatomegaly. The diagnosis of chronic vitamin A intoxication was based on a history of excessive vitamin A ingestion, clinical chemistry and needle biopsy of the liver. Besides retinol and retinyl ester, the serum concentration of retinol-binding protein (RBP) should be determined. Whereas the serum retinol concentration in chronic vitamin A intoxication often does not correlate with toxicity, the ratio between retinol and RBP and the concentration of retinyl ester is more sensitive. Morphological alterations are associated with the cumulative dosage of ingested vitamin A, whereas the daily amount of vitamin A determines the latency until pathological changes occur. The hormone-like, retinoid-receptor mediated molecular mechanism of action seems to be responsible for the multisystemic manifestations in chronic vitamin A intoxication syndrome.