Aims Guidelines for treatment of vitamin D deficiency (VDD) vary. We aimed to review the range of treatment regimens used locally to treat VDD and their effectiveness.
Methods We conducted a retrospective review of the records of consecutive patients referred to a children’s bone disease service with a putative diagnosis of VDD over a 14 month period. Data collected included treatment dose and duration, and pre and post-treatment serum 25-hydroxy vitamin D (25OHD) concentrations. Cases were excluded if these data were missing. Total dose per kg of vitamin D was calculated. In the absence of a contemporary weight, subjects were assumed to have a mean weight for age. Presence of rickets, history of fracture and adverse events were collected.
Results From 66 consecutive subjects, 29 with VDD had both pre and post-treatment 25OHD concentrations. Demographics – 12/29 South Asian, 7/29 Black African, 4/29 White British. 13/29 had radiographs; 2/13 showed rachitic features. In both cases, radiographs confirmed resolution after treatment. 4/29 had ever suffered fractures. Cholecalciferol treatment was variably instituted by primary or secondary care physicians. Daily doses ranged 3000–10000 U (median 6000); duration 4–12 weeks (median 6). 2/29 subjects received two doses of 100000 U each. Estimated total dose/kg ranged 3400–35000U/kg (mean 13500, SD 7400). The increase in serum 25OHD correlated with estimated total dose/kg (R2=29% p = 0.003). 2/29 remained vitamin D insufficient (34 and 45nmol/L). 5/29 subjects had an increase in 25OHD >200 nmol/L. These were all under 18 months of age and received estimated total doses 11000–35000 U/kg over 4–12 weeks. There were no recorded adverse effects.
Conclusion We found that commonly used regimens for treatment of VDD were effective in raising 25OHD to >50 nmol/L with no evidence of harm. A recent trial looking at a range of vitamin D doses in children under 12 months found higher doses of cholecalciferol led to hypervitaminosis. Although our study is limited by its retrospective character, small size, incomplete data and potential bias regarding subject selection, we found a variability in response to vitamin D treatment that suggests clinicians should perhaps consider the weight-related total dose when treating VDD, particularly in younger children.