Van Beresteyn 1986.

Study characteristics
Methods	Double‐blind, placebo‐controlled trial Participants were assigned to 2 groups according to a randomised block design that accounted for habitual calcium intake and BMI. The trial was conducted in the Netherlands.
Participants	58 normotensive healthy female dietetic students, not receiving any medical treatment at the time of recruitment Age: 20‐23 years Weight: 49‐76 kg
Interventions	Intervention group: Daily lemonade or apple juice with powder containing 1500 mg calcium ‐ calcium carbonate (1.251 g), citric acid (2.168 g), sodium‐hydrogen carbonate (0.5 g), and dextrose (2.88 g) Control group: Daily lemonade or apple juice placebo powder with citric acid (0.85 g), sodium‐hydrogen carbonate (0.5 g), dextrose (4.5 g), and corn‐flour (0. 1 g) Both groups received a low‐calcium diet (500 mg calcium a day) restricting intake of dairy products. Trial duration: 6 weeks
Outcomes	Difference for each individual between baseline blood pressure and final blood pressure Individual change in blood pressure during the experiment as indicated by the regression coefficient (slope) obtained from linear regression analysis of blood pressure versus time during the experimental period
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were assigned to 2 groups according to a randomised block design that accounted for habitual calcium intake and body mass index.
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Double‐blind, placebo‐controlled trial but methods not described
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants were reported in the results.
Selective reporting (reporting bias)	Low risk	All outcomes were reported.
Other bias	Low risk	Baseline characteristics were similar between the 2 groups.