Roth 1980.

Methods	This is a RCT conducted during August 1976 ‐ September 1977.
Participants	23 pregnant women were selected.
Interventions	Group A (11 patients): 1 x Tardyferon‐Fol tablet per day (80 mg iron sulphate, 80 mg mucoproteose, 350 µg folic acid) during pregnancy. Group B (12 patients): 1 x Tardyferon tablet per day (80 mg iron sulphate, 80 mg mucoproteose, no folic acid content) during pregnancy. Group A: 5 dropouts. Group B: 3 dropouts. Reasons for dropouts included irregular intake of the medication (3), change of residence (2), premature birth (2) and 1 unexplained failure to attend the final check‐up.
Outcomes	Haemoglobin level, red cell folate levels and serum folate levels (n = 23).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Randomised". Comment: insufficient information to make any judgement.
Allocation concealment (selection bias)	Unclear risk	Quote: "The tablets used in treatment were identical in appearance". Comment: insufficient information to make any judgement.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Quote: "Yes". Comment: insufficient information to make any judgement.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information to make any judgement.
Selective reporting (reporting bias)	Unclear risk	Insufficient information to make any judgement.
Other bias	Unclear risk	No other bias identified but insufficient information available to fully assess this 'Risk of bias' domain.