title: Harry M. Vars Research Award. Increase in lumbar spine bone mineral content in patients on long-term parenteral nutrition without vitamin D supplementation.
abstract: BACKGROUND
  We had previously shown that short-term withdrawal of vitamin D in patients with metabolic bone disease complicating home parenteral nutrition (HPN) corrected osteomalacia. We therefore conducted a prospective study of the effect of long term withdrawal of vitamin D in patients on home parenteral nutrition.
  
  
  METHODS
  Baseline measurements of bone mineral content, serum levels of calcium, phosphorus, parathormone, 25-OH and 1,25 (OH)2D; urinary calcium; and bone mineral density were measured. Then all parenteral vitamin D was withdrawn and the above parameters were followed for a mean of 4.5 years.
  
  
  RESULTS
  Lumbar spine bone mineral content (LSBMC) was 0.79 +/- 0.06 g/cm2 at the start of the study, well below the reference value, 1.16 +/- 0.13 g/cm2. Parathyroid hormone (PTH) (0.48 +/- 0.24 pmol/L) and 1,25-(OH)2D levels (22.8 +/- 7.9 pmol/L) were low and 25-hydroxyvitaniin D levels were normal (33.3 +/- 5.5 nmol/L) before removing vitandn D from the HPN solutions. After withdrawal of vitamin D for 4.5 +/- 0.2 years LSBMC increased from 0.79 +/- 0.06 to 0.93 0.07 g/cm2 (p < 0.005). Calcium phosphorus, magnesium and 25-hydroxyvitamin D did not change significantly, 1,25(OH)2D, and PTH levels became normal after withdrawal of vitamin D.
  
  
  CONCLUSIONS
  In selected patients with depressed PTH levels, long-term withdrawal of vitamin D during HPN increases LSBMC and levels of PTH and 1,25(OH)2D. There is no reduction of the mean level of 25-hydroxyvitamin D.
authors: Home Parenteral Nutrition Unit, Toronto Hospital, Ontario, Canada.
authors: A H
authors: AH
authors: Verhage
authors: W K
authors: WK
authors: Cheong
authors: J P
authors: JP
authors: Allard
authors: K N
authors: KN
authors: Jeejeebhoy
mesh_terms: D000328:Adult; D000368:Aged; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000378:metabolism / Q000628:therapy; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood / Q000652:urine; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D016331:Parenteral Nutrition, Home / Q000009:adverse effects; D010758:Phosphorus / Q000097:blood; D011446:Prospective Studies; D012016:Reference Values; D014807:Vitamin D / Q000008:administration & dosage*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D010758:Phosphorus; D002117:Calcitriol; D002112:Calcifediol; D002118:Calcium