title: Safety of long-term restrictive diets for peroxisomal disorders: vitamin and trace element status of patients treated for Adult Refsum Disease.
abstract: BACKGROUND
  Adult Refsum's Disease (ARD) is caused by defects in the pathway for alpha-oxidation of phytanic acid (PA). Treatment involves restricting the dietary intake of phytanic acid by reducing the intake of dairy-derived fat. The adequacy of micronutrient intake in patients with ARD is unknown.
  
  
  METHODS
  Patients established on the Chelsea low-PA diet had general diet macronutrients, vitamins and trace elements assessed using 7-day-weighed intakes and serial 24-h recalls. Intakes were compared with biochemical assessments of nutritional status for haematinics (ferritin), trace elements (copper, zinc, iron, selenium), water- (vitamin B6 , B12 and folate) and fat-soluble vitamins (A, D, E and K).
  
  
  RESULTS
  Eleven subjects (four women, seven men) were studied. Body mass index was 27 ± 5 kg/m(2) (range 19-38). All subjects had high sodium intakes (range 1873-4828 mg). Fat-soluble vitamin insufficiencies occurred in some individuals (vitamin A, n = 2; vitamin D, n = 6; vitamin E, n = 3; vitamin K, n = 10) but were not coincident. Vitamin B6 levels were normal or elevated (n = 6). Folate and 5-methyltetrahydrofolate concentrations were normal. Metabolic vitamin B12 insufficiency was suspected in four subjects based on elevated methylmalonic acid concentrations. Low copper and selenium intakes were noted in some subjects (n = 7, n = 2) but plasma levels were adequate. Iron, ferritin and zinc intakes and concentrations were normal.
  
  
  CONCLUSIONS
  Subjects with ARD can be safely managed on the Chelsea low PA without routine micronutrient supplementation. Sodium intake should be monitored and reduced. Periodic nutritional screening may be necessary for fat-soluble vitamins, vitamin B12 , copper or selenium.
authors.affiliation: Adult Refsum Disease Clinic, Chelsea & Westminster Hospital, London, UK.
authors.forename: E J
authors.initials: EJ
authors.lastname: Baldwin
authors.affiliation: Nutristasis Unit, Viapath, Guy's & St Thomas' Hospitals, London, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Harrington
authors.affiliation: Trace Element Laboratory, Imperial College Healthcare, Charing Cross Hospital, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Sampson
authors.affiliation: Adult Refsum Disease Clinic, Chelsea & Westminster Hospital, London, UK.
authors.forename: M D
authors.initials: MD
authors.lastname: Feher
authors.affiliation: Adult Refsum Disease Clinic, Chelsea & Westminster Hospital, London, UK.|Department of Metabolic Medicine/Chemical Pathology, Guy's & St Thomas' Hospitals, London, UK.
authors.forename: A S
authors.initials: AS
authors.lastname: Wierzbicki
mesh_terms: D000328:Adult; D000368:Aged; D004032:Diet; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D012035:Refsum Disease / Q000097:blood* / Q000178:diet therapy; D014131:Trace Elements / Q000097:blood*; D016896:Treatment Outcome; D014815:Vitamins / Q000097:blood*
chemical_list: D014131:Trace Elements; D014815:Vitamins; D005293:Ferritins