Prevalence and management of vitamin D deficiency in children with newly diagnosed coeliac disease: cohort study.

Background: Coeliac disease (CD) causes deficiency of various micronutrients including vitamin D, and there are no specific guidelines for treatment.

Aims: To determine the prevalence of vitamin D deficiency in children newly diagnosed with CD and the role of oral high-dose vitamin D in its treatment.

Methods: Calcium intake, sun exposure and biochemical and radiological parameters related to vitamin D deficiency were compared between 60 children aged 0-18 years diagnosed with CD and 60 healthy age- and sex-matched controls. The cases with serum 25(OH)D (<20 ng/ml) were given oral vitamin D (60,000 IU/week) and calcium (500 mg/day) for 12 weeks, along with a gluten-free diet (GFD); they were re-evaluated within a week of completion. The primary outcome measure was the serum 25(OH)D level, and secondary measures included serum calcium, phosphorus, alkaline phosphatase, parathormone and clinical and/or radiological rickets.

Results: The prevalence of vitamin D deficiency (25(OH)D <20 ng/ml) was significantly greater in the cases (=38, 63.3%) than in the controls (=27, 45.0%). Upon treatment, all 38 cases with vitamin D deficiency showed a significant rise in 25(OH)D levels along with normalisation of other biochemical abnormalities. Two children had 25(OH)D levels >100 ng/ml with no other feature suggestive of vitamin D toxicity.

Conclusions: Vitamin D deficiency is more prevalent in children with CD. Administration of oral high-dose vitamin D for 12 weeks along with a GFD leads to a robust response, indicating rapid mucosal recovery. The vitamin D dosage recommended for malabsorption states may be excessive in CD. ALP: alkaline phosphatase; CaBP: calcium-binding proteins; CD: coeliac disease; GFD: gluten-free diet; PTH: parathormone; RU: reproducibility units; 25(OH)D: 25 hydroxy vitamin D.