Endocrine Abstracts

End stage renal disease (ESRD) is characterised by decreased renal synthesis of 1,25-dihydroxyvitamin D (1,25D). Therapeutic use of 1,25D analogues for the management of renal bone disease is routine. However ESRD patients are also deficient in 25D (the immediate precursor of 1,25D). Since 2014 UK guidelines recommend diagnosis and treatment of 25D deficiency/insufficiency in people with chronic kidney disease, but make no recommendations for dosage or monitoring. This, together with i) a lack of appreciation for the physiological roles of vitamin D beyond mineral homeostasis, ii) a poor understanding of extra-renal 1,25D synthesis, and iii) a misconception that 1,25D therapy alone is sufficient, has meant hypovitaminosis D in ESRD remains prevalent. Vitamin D insufficiency/deficiency in the haemodialysis population of Coventry and Warwickshire was assessed and a clinical guideline for colecalciferol supplementation developed. Preliminary data relating to deficiency, safety, and efficacy are reported. A search of Web of Science, Cinahl, Embase, Medline, Cochrane, and Proquest (February–June 2014) identified 2847 citations. 17 full papers were appraised. The guideline recommends 40 000 IU colecalciferol weekly (for 3 months) if serum 25D <50 nmol/l and 20 000 IU weekly if serum 25D 50–75 nmol/l; to be continued long term unless levels increase to ≥150 nmol/l. To date, we have preliminary repletion data for 72 of our 350 haemodialysis patients. At baseline, virtually all patients (95.8%) had serum 25D <75 nmol/l (58.3% deficient, <30 nmol/l and 37.5% insufficient, 30–75 nmol/l). Only three patients had optimal levels (≥75 nmol/l). After 3 months supplementation 92% of patients had 25D ≥75 nmol/l (median 118.5; range 80–175). No patients remained deficient and only six patients remained insufficient (median 66.5 nmol/l; range 38–73). No hypercalcaemia was associated with colecalciferol supplementation. These data indicate hypovitaminosis D is prevalent in our haemodialysis population and this is likely to reflect UK haemodialysis patients. Initial data suggest vitamin D repletion following our local guideline is effective and safe.