title: Elevated serum vitamin B12 in cystic fibrosis.
abstract: In 62 patients with cystic fibrosis the serum vitamin B12 concentration ranged from 160-2600 pmol/l with a mean of 1 105 pmol/l. Both vitamin B12-binding proteins in the serum, transcobalamin II and R-binders, carried increased amounts of vitamin B12, but showed relatively normal levels of unsaturated vitamin B12-binding capacity. This combination is rather typical for hepatic dysfunction, although the recurrent pulmonary infections might exert an upward effect on plasma R-binder concentration through increased turnover of myeloid cells. A significant positive correlation between transcobalamin II-vitamin B12 and serum alkaline phosphatase suggests that transcobalamin II-bound vitamin B12 might be an early indicator of focal biliary cirrhosis, which is known to occur in these patients.
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000097:blood*; D006801:Humans; D014155:Transcobalamins / Q000032:analysis*; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D014155:Transcobalamins; D001219:Aspartate Aminotransferases; D000469:Alkaline Phosphatase; D014805:Vitamin B 12