Witham 2013.
| Study characteristics | ||
| Methods | Double‐blind, placebo‐controlled trial Blinding of outcome assessors stated 142 of 159 completed |
|
| Participants | Participants recruited from primary care, secondary care and the press, Scotland, UK 159 participants (82 men, 77 women), mean age 77 years Inclusion criteria: age 70 years and over, serum 25(OH)D level < 75 nmol/L, office systolic blood pressure > 140 mmHg Exclusion criteria: diastolic blood pressure > 90 mmHg, systolic blood pressure > 180 mmHg, hypertension known to be due to a correctable underlying medical or surgical cause; estimated glomerular filtration rate < 40 mL/minute, any liver function test (alanine aminotransferase, bilirubin, alkaline phosphatase) > 3 x upper limit of local normal range; albumin‐adjusted serum calcium > 2.60 mmol/L or < 2.15 mmol/L; known metastatic malignancy or sarcoidosis, a history of renal calculi, diagnosis of heart failure with left ventricular systolic dysfunction, atrial fibrillation, already taking vitamin D supplements |
|
| Interventions | 1. 100,000 IU vitamin D3 (Vigantol oil, Merck KgAA) every 3 months for 9 months (4 doses) 2. Matching placebo (Mygliol, Merck KgAA) every 3 months for 9 months (4 doses) Randomised 80; 79, completed 73; 69 Duration of treatment 9 months |
|
| Outcomes | Measured over a follow‐up of 12 months
1. Number of persons with all new fractures 2. Number of persons with hypercalcaemia, rise in serum creatinine > 20% 3. Number of persons dying |
|
| Notes | Data from personal communication from Miles Witham 15 January 2013 | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | States "minimisation algorithm" |
| Allocation concealment (selection bias) | Low risk | States "telephone‐based minimisation system" |
See Table 2 for abbreviations for vitamin D
AAT: aspartate aminotransferase APT: alkaline phosphatase BMC: bone mineral content BMD: bone mineral density BMI: body‐mass index Ca: calcium CT: computerised tomography DEXA: dual energy x‐ray absorptiometry ESR: erythrocyte sedimentation rate h: hour(s) HRT: hormone replacement therapy IV: intravenous(ly) μmol/L: micromoles per litre PO4: phosphate PTH: parathyroid hormone SD: standard deviation SPA: single photon absorptiometry