Li 2000.

Methods	"Patients were divided into 3 groups."
Participants	Women recruited at the outpatient clinic and labour ward of the First Afifliated Hospital of Xi’an Medical University between Aug 1996 to Dec 1998. High‐risk women with a predisposition to PIH.  Participants were required to be at 20‐24 weeks' gestation when entering the study, with a BMI index of < 24,  and an arterial pressure of < 11.3 kPa. Study states only that participants were "selected from our hospital outpatient clinic and labour ward".
Interventions	The first group (n = 29) received a daily dose of 600 mg of Calictrate‐D, the second group (n = 29) received 1200 mg if Calcitrate‐D daily, and the third group (n = 30), the control group, received nothing. From 20‐24 weeks till birth
Outcomes	Hypertension; biochemical studies
Notes	The outpatient clinic and labour ward of the First Afifliated Hospital of Xi’an Medical University. Aug 1996 to Dec 1998. No information on consent or ethical approval Source of funding: not clear (original article not in English). CoI: not clear.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	No placebo
Blinding of outcome assessment (detection bias) All outcomes	High risk	No placebo
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Loss to follow‐up not reported
Selective reporting (reporting bias)	Unclear risk	No information
Other bias	High risk	Methods not reported