Cherniack 2011.

Methods	Randomised, double‐blind, controlled trial using parallel group design (two intervention groups).
Participants	Country: United States. Number of participants randomised: 46 (2% women), aged 70 years an older (mean age 80). Inclusion criteria: community‐dwelling elderly veterans living in south Florida who were aged 70 and older. Exclusion criteria: current users of vitamin D or corticosteroids; or had hypo‐ or hypercalcaemia, hypercalciuria, hyperparathyroidism, chronic serum creatinine greater than 2.0 mg/dL, or cholestatic liver disease; or were unable to take medication daily.
Interventions	Participants were randomly assigned to receive: Intervention group 1: vitamin D3 (2000 IU) daily (n = 23); Intervention group 2 (Control group): placebo daily (n = 23); for a one year period. The 41 participants found to have inadequate calcium intake (< 1200 mg/d) according to dietary questionnaire were also dispensed a calcium supplement to provide adequate daily intake.
Outcomes	The primary outcomes were serum calcium, 25‐hydroxyvitamin D, parathyroid hormone, and 24‐hour urinary calcium.
Stated aim of study	"To determine the prevalence of hypovitaminosis D (serum 25‐hydroxyvitamin D < 32 ng/mL; HVD) in a population of elderly veterans and conduct a preliminary assessment of the efficacy of supplementation with cholecalciferol in correcting HVD".
Notes	Carlson Laboratories donated the cholecalciferol and placebo capsules.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Sequence generation was achieved using computer random number generation
Allocation concealment (selection bias)	Low risk	Allocation was controlled by a central and independent randomisation unit so that intervention allocations could not have been foreseen in advance of, or during, enrolment.
Blinding (performance bias and detection bias) All outcomes	Low risk	The outcome measurement is not likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) All outcomes	Low risk	There is insufficient information to assess whether the missing data mechanism in combination with the method used to handle missing data are likely to induce bias on the estimate of effect.
Selective reporting (reporting bias)	Low risk	Pre‐defined, or clinically relevant and reasonably expected outcomes are reported on.
Industry bias	Unclear risk	Carlson Laboratories donated the cholecalciferol and placebo capsules.
Other bias	Low risk	The trial appears to be free of other components that could put it at risk of bias.