Introduction and objectives CF bone disease is multi-factorial; UK guidelines for screening and treatment of CF bone disease are published.¹ Despite evidence of a key role for Vitamin K in bone formation, there is limited agreement on supplementation in CF. A previous 2005/06 survey² of bone health surveillance and Vitamin K use in CF reported wide variation in practice. The current survey aimed to ascertain practice 10 years on.

Methods Questionnaires were sent via email to all 25 UK paediatric CF centres. Data were collected on use of vitamins A, D, E and K including preparation, dose and criteria for Vitamin K supplementation. In addition, information was obtained on bone health surveillance including use of dual-energy X-ray absorptiometry (DXA) scanning to measure bone mineral density (BMD).

Results A 60% questionnaire response representing 2805 CF children was collected. All centres reported that >90% pancreatic insufficient patients receive multivitamin supplements and 12/15 centres reported >90% patients receive additional Vitamin E.

Only 3 centres routinely supplement Vitamin K, with only 1 reporting that >90% patients receive Vitamin K. Criteria for prescribing Vitamin K were deranged liver function (10/15), clotting (5/15), low Vitamin K levels (2/15), and low BMD (3/15). Vitamin K dosage varied from 0.3–10 mg/day, with most (12/15) prescribing 10 mg/day. Menadiol was mainly (10/15) used with some using Phytomenadione for younger patients. Four centres used AquaDEKs, whilst three reported limitations in prescribing AquaDEKs due to formulary constraints.

All centres measured vitamin D levels and 14/15 (94%) routinely perform DXA scans. Dietary calcium intake was assessed in 11/15 centres.

Conclusion Bone health surveillance is routinely undertaken in all paediatric CF centres, with Vitamin D levels and BMD (by DXA) measurement universal. Vitamin K prescribing (criteria and dose) is still heterogeneous. A Cochrane review³ of routine vitamin K supplementation in CF concluded that evidence is currently limited to two small trials, with further evidence needed to establish optimal dose and long-term benefit.

References 1 UK Cystic Fibrosis Trust Bone Mineralisation Working Group. Bone mineralisation in Cystic Fibrosis. London: UK Cystic Fibrosis Trust, 2007

2 Urquhart DS, Fitzpatrick M, Cope J. et al. Vitamin K prescribing patterns and bone health surveillance in UK children with cystic fibrosis. J Hum Nutr Diet. 2007;20:605–10

3 Jagannath VA, Fedorowicz Z, Thaker V. et al. Vitamin K supplementation for cystic fibrosis. Cochrane Database Syst Rev. 2015;1:CD008482