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

Optimisation of vitamin D status in global populations

Vitamin D is important for musculoskeletal health. Concentrations of 25-hydroxyvitamin D, the most commonly measured metabolite, vary markedly around the world and are influenced by many factors including sun exposure, skin pigmentation, covering, season and supplement use. Whilst overt vitamin D deficiency with biochemical consequences presents an increased risk of severe sequelae such as rickets, osteomalacia or cardiomyopathy and usually warrants prompt replacement treatment, the role of vitamin D supplementation in the population presents a different set of considerations. Here the issue is to keep, on average, the population at a level whereby the risk of adverse health outcomes in the population is minimised. This position paper, which complements recently published work from the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, addresses key considerations regarding vitamin D assessment and intervention from the population perspective. This position paper, on behalf of the International Osteoporosis Foundation Vitamin D Working Group, summarises the burden and possible amelioration of vitamin D deficiency in global populations. It addresses key issues including screening, supplementation and food fortification.

The clinical relevance of native vitamin D in pediatric kidney disease

Hypovitaminosis D has been reported to be common in chronic kidney disease (CKD) as well as in proteinuric disorders. We reviewed available evidence to assess clinically relevant effects of low vitamin D status and native vitamin D (NVD) therapy, in pediatric renal diseases. Online medical databases were searched for articles related to vitamin D status, associations of hypovitaminosis D and effects of NVD therapy in kidney disease. Hypovitaminosis D was associated with worse skeletal, cardiovascular, inflammatory, and renal survival outcomes in CKD. Low serum 25 hydroxy-vitamin D (25[OH]D) levels correlated positively with glomerular filtration rate and negatively with serum parathyroid (PTH) levels. However, to date, evidence of benefit of NVD supplementation is restricted mainly to improvements in serum PTH, and biochemical 25[OH]D targets form the basis of clinical practice recommendations for NVD therapy. In nephrotic syndrome (NS) relapse, studies indicate loss of 25[OH]D along with vitamin D binding protein in urine, and serum total 25[OH]D levels are low. Preliminary evidence indicates that free 25[OH]D may be a better guide to the biologically active fraction. NVD therapy in NS does not show consistent results in improving skeletal outcomes and hypercalciuria has been reported when total 25[OH]D levels were considered as indication for therapy. NVD formulations should be regularised, and therapy monitored adequately to avoid adverse effects.

The Use of Special-Order Products in England between 2012-2020: An Insight into The Need for Point-of-Care Manufacturing

Point-of-care manufacturing such as 3D printing has recently received significant attention from regulatory bodies and the pharmaceutical industry. However, little information is available on the quantity of the most prescribed patient-specific items, their dosage form, and why they were required to be dispensed. In England, 'Specials' are unlicensed medicines formulated to meet the requirements of a specific prescription, prescribed if no suitable licensed alternative exists. This work aims to quantify and examine trends in the prescribing of 'Specials' in England during 2012-2020, using the NHS Business Services Authority (NHSBSA) database. Quarterly prescription data from NHSBSA for the top 500 'Specials' by quantity from 2012-2020 were compiled yearly. The changes in net ingredient cost, the number of items, British National Formulary (BNF) drug category, dosage form, and a potential reason for requiring a 'Special' were identified. In addition, the cost-per-unit was calculated for each category. The total spending on 'Specials' decreased by 62% from £109.2M in 2012 to £41.4M in 2020, primarily due to a 55.1% reduction in the number of 'Specials' items issued. The most frequently prescribed dosage form type of 'Special' was oral dosage forms (59.6% of all items in 2020) particularly oral liquids. The most common reason for prescribing a 'Special' was an inappropriate dosage form (74% of all 'Specials' in 2020). The total number of items dropped over the 8 years as commonly prescribed 'Specials' such as melatonin and cholecalciferol became licensed. In conclusion, the total spending on 'Specials' dropped from 2012-2020 primarily due to a reduction in the number of 'Specials' items issued and pricing change in the Drug tariff. Based on the current demand for 'special order' products, these findings are instrumental for formulation scientists to identify 'Special' formulations to design the next generation of extemporaneous medicine to be produced at the point of care.

Association between vitamin D and incident herpes zoster: a UK Biobank study

BACKGROUND

Vitamin D has immunomodulatory effects, but any association with herpes zoster (HZ) is unclear.

AIM

To explore the association between vitamin D status and risk of incident HZ in adults in the UK.

DESIGN AND SETTING

A cohort study involving participants of UK Biobank (a database containing the health information from half a million individuals) across England, Wales, and Scotland, who had at least one vitamin D testing result with linked primary care electronic health records.

METHOD

The primary exposure was vitamin D status, categorised as deficient (<25 nmol/L), insufficient (25-49 nmol/L), or sufficient (≥50 nmol/L). The secondary exposures were self-reported vitamin D supplementation at baseline assessment and vitamin D prescription records. The outcome was diagnosed incident HZ, identified from linked primary care or hospital inpatient records. Weibull regression was used, adjusting for potential confounders, including demographic factors, comorbidities, and immunosuppression.

RESULTS

In total, 177 572 eligible participants were included in the analysis, with a mean follow-up time of 10.1 years (standard deviation 1.9 years). No evidence showed that low vitamin D was associated with a higher incidence of HZ, compared with people with sufficient vitamin D (deficient: adjusted hazard ratio [HR] 0.99, 95% confidence interval [CI] = 0.90 to 1.10; insufficient: HR 1.03, 95% CI = 0.96 to 1.10). No evidence was found that supplementing vitamin D or receiving vitamin D prescription was associated with HZ incidence (supplementation: HR 0.88, 95% CI = 0.67 to 1.16; prescription: HR 1.11, 95% CI = 0.91 to 1.34).

CONCLUSION

No association of vitamin D status, supplementation, or prescription with incident HZ was observed. No evidence supported vitamin D supplementation as a strategy to prevent HZ.

Nephrocalcinosis in children who received high-dose vitamin D

BACKGROUND

Vitamin D supplements are readily available as over-the-counter preparations. However, although rare, cases of vitamin D overdose still occur and are associated with nephrocalcinosis and life-threatening hypercalcemia. Errors in manufacturing of nutritional supplements may be a cause of vitamin D intoxication in children. This study aimed to identify factors associated with vitamin D overdose-related nephrocalcinosis in children due to manufacturing errors in supplements.

METHODS

This retrospective study reviewed medical charts of pediatric patients with non-registered supplement-related vitamin D overdose at a tertiary referral hospital between 2006 and 2011. Clinical and laboratory characteristics of patients with or without nephrocalcinosis were evaluated. Receiver operating characteristics curve and area under the receiver operating characteristics curve were used to determine the most predictive value of each characteristic.

RESULTS

A total of 44 patients (males: 29; age: 7-62 months) were included. Age ≤ 16.5 months, body weight ≤ 10.25 kg, body height ≤ 78.5 cm, body surface area (BSA) ≤ 0.475 m², 25-hydroxyvitamin D₃ ≥ 143 ng/mL, and calcium ≥ 10.65 mg/dL were predictive of developing nephrocalcinosis with a sensitivity and specificity of > 60%. Univariant analysis revealed that BSA was the most significant anthropometric prognostic factor (odds ratio: 12.09; 95% confidence interval: 2.61-55.72; P = 0.001).

CONCLUSIONS

Children with smaller BSAs were more vulnerable to high-dose vitamin D₃-related nephrocalcinosis. Physicians and parents should be aware of the potential adverse effects of vitamin D overdose in children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Establishing an appropriate level of Vitamin D supplementation in paediatric patients with Recessive Dystrophic Epidermolysis Bullosa

BACKGROUND

Paediatric patients with Recessive Dystrophic Epidermolysis Bullosa (RDEB) are at risk of vitamin D deficiency due to large areas of skin being covered with dressings, reduced mobility and impaired nutritional intake.

METHODS

Patients attending the EB tertiary MDT clinic and diagnosed with RDEB were included. Serum levels of total 25 (OH) D were retrospectively recorded between 2012-2018. Data from clinical records on supplements, Bone Mineral Density (BMD) Z scores, compliance, enteral feeds and/or formula was also recorded.

RESULTS

24 patients met the inclusion criteria: 20 RDEB severe, 3 RDEB inversa and 1 had RDEB intermediate. 21/24 (88%) of patients were advised to take a vitamin D3 supplement, with the remaining three receiving sufficient intake from formula/enteral feeds. 13/24 (54%) showed vitamin D deficiency or insufficiency. Nine of these thirteen (69%) successfully took vitamin D supplements and levels became sufficient (>50nmol/L). The remaining four patients (31%) had persistent insufficient levels due to non-compliance with supplements. Reasons for non-compliance were palatability, forgetting or cost. The dose required to maintain sufficient serum levels increased with age, up to 300% of the RNI.

CONCLUSION

All patients with RDEB require a supplement or formula/sip feed containing vitamin D to maintain sufficient serum vitamin D. The dose required increases with age and can be three times higher than the recommended nutrient intakes (RNI) for the normal population. Compliance may improve using a once-weekly loading dose of vitamin D3. Vitamin D deficiency was not solely causative of a low BMD Z score.

Case Report: Severe Hypercalcemia Following Vitamin D Intoxication in an Infant, the Underestimated Danger of Dietary Supplements

Vitamin D supplementation is routinely introduced in infants, according to medical guidelines. However, vitamin D overdose can result in life-threatening hypercalcemia. We report the case of a 3-month-old infant who suffered from severe hypercalcemia. Upon detailed questioning of the parents, a vitamin D administration error has been identified. Indeed, the parents had followed the advice of their midwife. They substituted the prescribed medicinal vitamin D by a dietary supplement, different in concentration and dosing, without performing the dose conversion needed. In fact, many different medications and dietary supplements with vitamin D exist, offering various concentrations and units of measurement. This case highlights the pivotal role of therapeutic education. Broadly, there is a need for harmonization of the regulation and labeling of dietary supplements and medications containing vitamin D.

Trends, geographical variation and factors associated with melatonin prescribing in general practices in England: A practice-level analysis

An overview of melatonin prescribing trends and variation in England is described in this study. Prescription reimbursement data for melatonin in England were extracted from publicly available primary care datasets between 2008-2019. Melatonin prescribing rates, cost and product license status were described over time. Potential factors associated with melatonin prescribing were investigated using Poisson regression. Melatonin prescribing increased from 2.0 to 19.9 per 1000 people between 2008 and 2019. While prescriptions for licensed products increased from 6.5% to 88.2%, spending on unlicensed products was £10 million and accounted for 23.3% of the total prescription cost in 2019. Practices with a higher proportion of children and older people and those serving more deprived patient populations were associated with a higher rate of prescribing (rate ratio = 1.51, 1.66 and 1.59, respectively). Melatonin prescribing in England has increased exponentially over the last decade, with substantial spending on unlicensed products of unknown quality. Patient-level analysis research is needed.