Parameter for univariate sensitivity analyses | Base-case estimate* | Assumption and/or (reference) | Range or measure of variation evaluated |

% Reduction in all-cause mortality | 7% | A meta-analysis of RCTs; RR: 0.93; 95% CI 0.88 to 0.989 | 1%–10% |

The risk reduction of fractures (hip and non-hip) | 16% (hip)10 12 20% (non-hip, less severe fractures)12 | A meta-analysis of RCTs; for vitamin D plus calcium, RR, 0.84 (95% CI 0.72 to 0.97) for hip fracture.10 A meta-analysis of RCTs; for vitamin D dose >400 IU/day, RR was 0.82 (95% CI 0.69 to 0.97) for hip fractures, and RR: 0.80 (95% CI 0.72 to 0.89) for non-vertebral fractures.12 | 1%–150% (of the base-case estimates) |

Discount rate for costs and benefits | 4% | 8 | 0%–6% |

Serum 25(OH)D measurement cost | €21.50 | Assumed to be greater than the PPP equivalent of £17 per test23 | 50% increase in the base-case estimate |

Invasive cancer end-of-life care cost | €6487 | 18 | 50% increase in the base-case estimate |

Average annual discounted cost of serum 25(OH)D measurement, GP visit, plus vitamin D acquisition cost† | €120.59 (non-discounted, €129.44) | Based on the average cost over a 5-year period (with/without discounting) | 50% increase in the base-case cost of serum 25(OH)D measurement, and the cost of GP visit, respectively |

% Reduction in all-cause mortality | 7% | 9 | 4.9% (30% reduction from base-case) |

The risk reduction of fractures (hip and non-hip) | 16% (hip) 20% (non-hip) | 10 12 | 11% (hip) 14% (non-hip) (30% reduction from base-case) |

Serum 25(OH)D measurement cost | €21.50 | Assumed to be greater than the PPP equivalent of £17 per test23 | 30% increase in the base-case estimate |

Invasive cancer end-of-life care cost | €6487 | 18 | 30% increase in the base-case estimate |

Average annual discounted cost of serum 25(OH)D measurement, #GP visit, plus vitamin D acquisition cost | €120.59 (non-discounted, €129.44) | Based on the average cost over a 5-year period (with/without discounting) | 30% increase in the base-case cost of serum 25(OH)D measurement, and the cost of GP visit, respectively |

*Cost of a GP visit derived from data from Primary Care Reimbursement Service (PCRS) Statistical Analysis of Claims and Payments (2016).24

†All costs are 2020 costs, with inflation of costs to €(2020) values26 where required.

PPP, purchasing power parity; RCTs, randomised controlled trials.