Mirghafourvand 2015.

Methods	3‐arm randomised controlled trial.
Participants	Describe setting: Tabriz‐Iran Inciusion criteria: pregnant women,14–34 weeks of gestation, between 18 and 35 years of age who suffered from leg cramps at least twice a week. Exclusion criteria: history of chronic diseases, kidney problems, osteomalacia, active thyroid or parathyroid diseases, endocrine disorders, hypertension, use of diuretics, calcium‐blockers intake, chronic hypertension, and history of allergy to the study supplements.
Interventions	Experimental intervention: vitamin D (1000 units) (42 women) or vitamin D plus calcium complements (42 women) (300 mg of calcium carbonate and 1000 units of vitamin D) Comparison intervention: placebo (42 women)
Outcomes	Sleep quality in pregnant women with leg cramps
Notes	Dates of study: July 2013 to April 2014 Funding sources: nil Declarations of interest: there are no conflicts of interest.