Vitamin B deficiencies in a critically ill autistic child with a restricted diet.

An 11-year-old male with autism became less responsive and was hospitalized with hepatomegaly and liver dysfunction, as well as severe lactic acidosis. His diet for several years was self-limited exclusively to a single "fast food"-a particular type of fried chicken-and was deficient in multiple micronutrients, including the B vitamins thiamine and pyridoxine. Lactic acidosis improved rapidly with thiamine; 2 weeks later, status epilepticus-with low serum pyridoxine-resolved rapidly with pyridoxine. Dietary B vitamin deficiencies complicated the care of this critically ill autistic child and should be considered in this setting.