Quality and use of unlicensed vitamin D preparations in primary care in England: Retrospective review of national prescription data and laboratory analysis

TY - JOUR

T1 - Quality and use of unlicensed vitamin D preparations in primary care in England

T2 - Retrospective review of national prescription data and laboratory analysis

AU - Wan, Mandy

AU - Patel, Anish

AU - Patel, Jignesh

AU - Greta, Rait

AU - Jones, Stuart

AU - Shroff, Rukshana

N1 - Funding Information: M.W. is a doctoral student supported by a Clinical Doctoral Research Fellowship grant (ICA‐CDRF‐2016‐02‐057) from the UK National Institute for Health Research (NIHR). R.S. holds a Career Development Fellowship with the NIHR. Part of the work took place in the Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health and Social Care. Funding Information: M.W. is a doctoral student supported by a Clinical Doctoral Research Fellowship grant (ICA-CDRF-2016-02-057) from the UK National Institute for Health Research (NIHR). R.S. holds a Career Development Fellowship with the NIHR. Part of the work took place in the Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health and Social Care. Publisher Copyright: © 2020 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society

PY - 2021/3

Y1 - 2021/3

N2 - Aim: To evaluate the type (licensed vs unlicensed) and cost of preparations used to fulfil vitamin D prescriptions in England over time, and to compare measured vitamin D content of selected vitamin D preparations against labelled claim. Methods: Retrospective analysis of vitamin D prescription data in primary care in England (2008-2018). Laboratory analysis of 13 selected vitamin D preparations. Results: Alongside a rise in the number of oral licensed colecalciferol preparations from 0 to 27 between 2012 and 2018, the proportion of vitamin D prescriptions in which licensed vitamin D preparations were supplied increased from 11.8 to 54.2%. However, the use of unlicensed food supplements (dose strength 400-50 000 IU) remained high, accounting for 39.7% of vitamin D prescriptions in 2018. The two licensed preparations showed mean (±SD) vitamin D content of 90.9 ± 0.7% and 90.5 ± 3.9% of the labelled claimed amount, meeting the British Pharmacopeia specification for licensed medicines (90-125% of labelled claim). The 11 food supplements showed vitamin D content ranging from 41.2 ± 10.6% to 165.3 ± 17.8% of the labelled claim, with eight of the preparations failing to comply with the food supplement specification (80-150% of labelled claim). Conclusions: Despite the increasing availability of quality assured licensed preparations, food supplements continued to be used interchangeably with licensed preparations to fulfil vitamin D prescriptions. Food supplements, manufactured under less stringent quality standards, showed wide variations between measured and declared vitamin D content, which could lead to the risk of under- and over-dosing.

AB - Aim: To evaluate the type (licensed vs unlicensed) and cost of preparations used to fulfil vitamin D prescriptions in England over time, and to compare measured vitamin D content of selected vitamin D preparations against labelled claim. Methods: Retrospective analysis of vitamin D prescription data in primary care in England (2008-2018). Laboratory analysis of 13 selected vitamin D preparations. Results: Alongside a rise in the number of oral licensed colecalciferol preparations from 0 to 27 between 2012 and 2018, the proportion of vitamin D prescriptions in which licensed vitamin D preparations were supplied increased from 11.8 to 54.2%. However, the use of unlicensed food supplements (dose strength 400-50 000 IU) remained high, accounting for 39.7% of vitamin D prescriptions in 2018. The two licensed preparations showed mean (±SD) vitamin D content of 90.9 ± 0.7% and 90.5 ± 3.9% of the labelled claimed amount, meeting the British Pharmacopeia specification for licensed medicines (90-125% of labelled claim). The 11 food supplements showed vitamin D content ranging from 41.2 ± 10.6% to 165.3 ± 17.8% of the labelled claim, with eight of the preparations failing to comply with the food supplement specification (80-150% of labelled claim). Conclusions: Despite the increasing availability of quality assured licensed preparations, food supplements continued to be used interchangeably with licensed preparations to fulfil vitamin D prescriptions. Food supplements, manufactured under less stringent quality standards, showed wide variations between measured and declared vitamin D content, which could lead to the risk of under- and over-dosing.

KW - drug utilisation

KW - pharmacy

KW - quality use of medicines

UR - http://www.scopus.com/inward/record.url?scp=85089959822&partnerID=8YFLogxK

U2 - 10.1111/bcp.14521

DO - 10.1111/bcp.14521

M3 - Article

C2 - 32803772

AN - SCOPUS:85089959822

SN - 0306-5251

VL - 87

SP - 1338

EP - 1346

JO - British Journal of Clinical Pharmacology

JF - British Journal of Clinical Pharmacology

IS - 3

ER -