What do systematic reviews say?

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

It is very uncertain whether interventions (vitamin B1, mefenamic acid, tranexamic acid) changes side effects: gastrointestinal disturbances (diarrhoea, lower… compared with placebo or active comparators (desmopressin, sodium diclofenac,… (very low certainty).

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  OR 4.69 [1.2, 18.44]
  1 study · 38 participants
  Very low

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 100 participants
  Low
• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 24 participants
  Very low

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 100 participants
  Low
• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 110 participants
  Low

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 100 participants
  Low
• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 290 participants
  Very low

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

Interventions (vitamin B1, mefenamic acid, tranexamic acid) showed no clear difference in side effects: headache compared with placebo or active comparators (desmopressin, sodium diclofenac,… (low certainty).

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  OR 0.58 [0.18, 1.92]
  1 study · 100 participants
  Low

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

Interventions (vitamin B1, mefenamic acid, tranexamic acid) showed no clear difference in side effects: vomiting compared with placebo or active comparators (desmopressin, sodium diclofenac,… (low certainty).

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  OR 0.74 [0.25, 2.18]
  1 study · 100 participants
  Low

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 110 participants
  Low
• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 152 participants
  Low

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

The review found no eligible studies for this question.

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Interventions (vitamin B1, mefenamic acid, tranexamic acid) vs placebo or active comparators (desmopressin, sodium diclofenac, flavonoids)

• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 94 participants
  Low
• Interventions to prevent or treat heavy menstrual bleeding or pain associated with intrauterine‐device use 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 38 participants
  Very low

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

It is very uncertain whether vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic… changes oral cancer development compared with placebo or no treatment (very low certainty).

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  24 months (treatment lasted 12 months)
  RR 0.11 [0.01, 2.05]
  1 study · 85 participants
  Very low

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  4 to 12 months
  SoF 1, Clinical resolution (not completely resolved) at 4 to 12 months: 'Studies could not be combined in meta-analysis. One study evaluated topical treatment and did not find evidence of benefit; 3 studies of systemic…
  4 studies
  GRADE not reported

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic… probably leads to lower improvement of histological features (not improved) compared with placebo or no treatment (moderate certainty).

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  3 months
  RR 0.43 [0.24, 0.76]
  1 study · 41 participants
  Moderate

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  4 to 12 months
  SoF 1, Safety of the intervention at 4 to 12 months: '3 studies (1 each evaluating topical acitretin, topical 13-cis-retinoic acid, 200,000 IU per week of vitamin A) found no adverse effects. Systemic 13-cis-retinoic…
  4 studies
  GRADE not reported

Provision of maize flour or maize flour products fortified with iron plus other vitamins and minerals vs unfortified maize flours or maize flour products

It is very uncertain whether provision of maize flour or maize flour products fortified with iron… changes anaemia (defined as haemoglobin (Hb) below WHO cut‐off, adjusted for… compared with unfortified maize flours or maize flour products (very low certainty).

• Fortification of maize flour with iron for controlling anaemia and iron deficiency in populations 2018 · Cochrane Headline outcomes only
  RR 0.9 [0.58, 1.4]
  2 studies · 1027 participants
  Very low

Provision of maize flour or maize flour products fortified with iron plus other vitamins and minerals vs unfortified maize flours or maize flour products

It is very uncertain whether provision of maize flour or maize flour products fortified with iron… changes iron deficiency (as defined by trialists, based on a biomarker of… compared with unfortified maize flours or maize flour products (very low certainty).

• Fortification of maize flour with iron for controlling anaemia and iron deficiency in populations 2018 · Cochrane Headline outcomes only
  RR 0.75 [0.49, 1.15]
  2 studies · 1102 participants
  Very low

Provision of maize flour or maize flour products fortified with iron plus other vitamins and minerals vs unfortified maize flours or maize flour products

• Fortification of maize flour with iron for controlling anaemia and iron deficiency in populations 2018 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 1144 participants
  Very low

Provision of maize flour or maize flour products fortified with iron plus other vitamins and minerals vs unfortified maize flours or maize flour products

• Fortification of maize flour with iron for controlling anaemia and iron deficiency in populations 2018 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 584 participants
  Very low

Provision of maize flour or maize flour products fortified with iron plus other vitamins and minerals vs unfortified maize flours or maize flour products

The review found no eligible studies for this question.

• Fortification of maize flour with iron for controlling anaemia and iron deficiency in populations 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Dietary supplements (alpha lipoic acid +/- vitamins/lycopene/green tea; hypericum; Catuama; lycopene) vs placebo

• Interventions for treating burning mouth syndrome 2016 · Cochrane All outcomes

  short-term (up to 3 months)
  SoF5 Dietary supplements vs placebo. Symptom relief short-term: insufficient or contradictory evidence regarding benefit of any evaluated dietary supplement; 628 participants (12 RCTs); very low. Subgroups: ALA without…
  12 studies · 628 participants
  Very low

Homocysteine‐lowering interventions (Folic Acid, Vitamin B6 and Vitamin B12) vs placebo or usual care

Homocysteine‐lowering interventions (Vitamin B6 (pyridoxine;… showed no clear difference in myocardial infarction compared with placebo or standard care (high certainty).

• Homocysteine‐lowering interventions for preventing cardiovascular events 2017 · Cochrane Headline outcomes only
  RR 1.02 [0.95, 1.1]
  12 studies · 46699 participants
  High