Dietary deficiencies and psychiatric symptoms

Which of the following vitamin deficiencies is most likely to lead to a triad of
gastrointestinal disturbance, dermatological symptoms and a heterogeneous
constellation of psychiatric symptoms?
A. Niacin
B. Vitamin A
C. Vitamin B1
D. Vitamin C

E. Vitamin D
Answer
A Nicotinic acid, or niacin, deficiency (A) is also known as pellagra.
It classically manifests with gastrointestinal symptoms, such as
diarrhoea, anorexia and gastritis. The dermatological manifestations
include symmetrical, bilateral bullous lesions in sun-exposed areas.
The psychiatric symptoms initially manifest as apathy, depression, or
irritability. However, in later stages there are more florid symptoms
resembling delirium, psychosis or a Korsakoff-like presentation. If
identified, treatment with nicotinic acid usually leads to prompt and
dramatic improvements in mental state. Vitamin A deficiency (B)
is associated with night-blindness, dry skin and hair and anaemia.
Thiamine, or vitamin B1 deficiency (C) is known as beriberi. The classical
symptoms of this disorder are neuropathy and heart failure. Acute
depletion of thiamine, as seen in alcohol dependence, leads to Wernicke’s
encephalopathy. Vitamin C deficiency (D) leads to scurvy, characterized
by anorexia, diarrhoea, irritability, anaemia, gingival haemorrhage, poor
wound healing, leg pain and swelling over the long bones. Vitamin D
deficiency (E) leads to rickets in children and osteomalacia in adults.
There is now growing evidence of some link with vitamin D to cognitive
functioning. There are speculations about its role in seasonal affective
disorder whereby patients have normal mental function during the year
but during a particular season, e.g. winter, will display a mood disorder
such as depression year after year during that season.