Background: Routine surveillance would be valuable for vitamin D deficiency as symptomatic vitamin D deficiency may be common in Scotland.
Aim: To assess the effectiveness of an electronic surveillance system to determine the current incidence of hospital-based presentation of childhood vitamin D deficiency in Scotland.
Methods: Active surveillance was performed for 2 years as part of an electronic web-based surveillance programme by the Scottish Paediatric Surveillance Unit. Notifications were followed by completion of a questionnaire. To further examine the validity of the system, cases with severe vitamin D deficiency in Glasgow and Edinburgh were identified from the regional laboratory and their clinical details were checked against those identified through the surveillance system.
Results: Between September 2009 and August 2011, 109 cases of vitamin D deficiency were notified. The majority of cases (n=82) were reported in Glasgow with an annual incidence of 41 cases per year. Fourteen cases were reported in Edinburgh during the first year of the study and two cases during the second year. At the time of clinical diagnosis, the median age of the children was 2 years (range 3 months-16 years). Cross-validation of data showed that among symptomatic cases that had a measured serum vitamin D of <14 nmol/L, 89% of eligible cases had been reported in Glasgow and 33% of cases had been reported in Edinburgh.
Conclusion: The incidence of vitamin D deficiency remains high in Scotland. An electronic surveillance system can provide data for studying the epidemiology of vitamin D deficiency but may underestimate the number of positive cases.