Re: British Paediatric and Adolescent Bone Group’s position statement on vitamin D deficiency
We have read with interest the British Paediatric and Adolescent Bone Group’s position statement on vitamin D deficiency (1). While we welcome the interest of this group on the effects of vitamin D on the skeleton, we concur with Shore et al (2) in that “rickets has clear histopathological findings and hence it is ultimately a histopathological entity” and as such, “it is too dogmatic to suggest that subclinical rickets does not exist” (2).
The correlation between clinical, radiological, biochemical and histological findings is poor (3). An autopsy series from 1909 comparing post mortem radiology and histology showed a higher incidence of rickets on histopathology than on radiology (4). The old literature is full of similar findings (5). Our experience is also similar: histopathological changes in the growth plate (from mild abnormalities to frank rickets) and abnormalities in the endochondral ossification can be present with normal radiology and with levels above 50nmol/L (Personal communication) (Figure 1).
Conventional radiography, while a useful clinical tool, is not sensitive enough to determine the presence of rickets.
Currently, there are no objective methods that allow assessment of bone fragility, either in clinical or in subclinical rickets. The implication of subclinical rickets as a risk factor for fractures is yet to be investigated.
Dr Irene Scheimberg, Consultant Paediatric and Perinatal Pathologist, Barts Health NHS Trust
Dr Marta Cohen, Consultant Paediatric and Perinatal Pathologist, Sheffield Children’s Hospital NHS Trust
1. Arundel P et al. British Paediatric and Adolescent Bone Group’s position statement on vitamin D deficiency. BMJ 2012; 345
2. Shore RM, Chesney RW. Rickets: part II. Minisymposium. Pediatr Radiol. Epub 21/11/12
3. Pettifor et al. diagnosis of subclinical rickets. Arch Dis Child. 1980; 55: 155-7
4. Schmorl G as cited in Shore and Chesney
5. Hess AF, Unger LJ. Infantile rickets: the significance of clinical, radiographic and chemical examinations in its diagnosis and incidence. Am J Dis Child 1922
Figure 1: Infant who died Suddenly and Unexpectedly. The histology of the ribs and the long bones showed marked irregularity of the columns of chondrocytes with accompanying vessels penetrating the growth plate (a); the cartilage failed to mineralise, leaving islands of cartilage an excess osteoid in the metaphysis (b). The radiology, twice reviewed by a paediatric radiologist, did not show any evidence of rickets.