LABORATORY ASSESSMENT OF NUTRITIONAL METABOLIC BONE-DISEASE IN INFANTS

Objectives: There are numerous laboratory investigations available for the assessment of an infant with suspected metabolic bone disease (MB D); thus, comprehensive laboratory investigations on every aspect of M BD would impose unnecessary stress to the infant and the costs involve d would be prohibitive. An overview of the assessment of an infant wit h suspected MBD, in particular, nutrition-related bone disease, is pre sented. Our objectives include an understanding of: 1. the importance of appropriate information from history and physical examination to gu ide the laboratory investigations; 2. relevance and limitations of spe cific laboratory investigations: a. radiologic studies include diagnos tic radiographs and quantitative bone mass determination by dual energ y x-ray absorptiometry, b. biochemical measurements to determine miner al homeostasis and bone turnover, c. vitamin (vitamin D metabolites) a nd hormonal (parathyroid hormone and calcitonin) measurements; with re spect to diagnosis and monitoring of the natural progress or response to therapy. Conclusion: Relevant information from clinical history and physical examination, and an understanding of the role and limitation s of various laboratory investigations, would allow the optimal utiliz ation of laboratory tests in the assessment of an infant with MBD.