What do systematic reviews say?

Vitamin D plus calcium vs calcium

The review found no eligible studies for this question.

• Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin A vs no supplementation

Supplemental vitamin A showed no clear difference in neonatal death compared with no supplementation (moderate certainty).

• Vitamin A supplementation to prevent mortality and short‐ and long‐term morbidity in very low birth weight infants 2016 · Cochrane Headline outcomes only
  RR 0.86 [0.66, 1.11]
  6 studies · 1165 participants
  Moderate

Vitamin A vs no supplementation

Supplemental vitamin A showed no clear difference in chronic lung disease (oxygen use at 28 days in survivors) compared with no supplementation (moderate certainty).

• Vitamin A supplementation to prevent mortality and short‐ and long‐term morbidity in very low birth weight infants 2016 · Cochrane Headline outcomes only
  RR 0.93 [0.86, 1.01]
  7 studies · 1070 participants
  Moderate
• Vitamin A supplementation to prevent mortality and short‐ and long‐term morbidity in very low birth weight infants 2016 · Cochrane Headline outcomes only
  RR 0.87 [0.77, 0.99]
  5 studies · 986 participants
  Moderate

Vitamin A vs no supplementation

Supplemental vitamin A probably leads to lower death or chronic lung disease (oxygen use at 28 days) compared with no supplementation (moderate certainty).

• Vitamin A supplementation to prevent mortality and short‐ and long‐term morbidity in very low birth weight infants 2016 · Cochrane Headline outcomes only
  RR 0.93 [0.88, 0.99]
  6 studies · 1165 participants
  Moderate
• Vitamin A supplementation to prevent mortality and short‐ and long‐term morbidity in very low birth weight infants 2016 · Cochrane Headline outcomes only
  RR 0.92 [0.84, 1.01]
  4 studies · 1089 participants
  Moderate

Vitamin A vs no supplementation

Supplemental vitamin A showed no clear difference in death before 36 weeks' postmenstrual age compared with no supplementation (moderate certainty).

• Vitamin A supplementation to prevent mortality and short‐ and long‐term morbidity in very low birth weight infants 2016 · Cochrane Headline outcomes only
  RR 1 [0.77, 1.29]
  4 studies · 1089 participants
  Moderate

Vitamin A vs no supplementation

Supplemental vitamin A showed no clear difference in neurodevelopmental impairment at 18 to 22 months compared with no supplementation (low certainty).

• Vitamin A supplementation to prevent mortality and short‐ and long‐term morbidity in very low birth weight infants 2016 · Cochrane Headline outcomes only
  RR 0.89 [0.74, 1.08]
  1 study · 538 participants
  Low

Vitamin E + vitamin C vs placebo

Vitamin C and vitamin E showed no clear difference in total fetal loss compared with placebo (high certainty).

• Vitamin supplementation for preventing miscarriage 2016 · Cochrane Headline outcomes only
  RR 1.14 [0.92, 1.4]
  7 studies · 18949 participants
  High

Vitamin E + vitamin C vs placebo

Vitamin C and vitamin E showed no clear difference in early or late miscarriage compared with placebo (moderate certainty).

• Vitamin supplementation for preventing miscarriage 2016 · Cochrane Headline outcomes only
  RR 0.9 [0.65, 1.26]
  4 studies · 13346 participants
  Moderate

Vitamin E + vitamin C vs placebo

Vitamin C and vitamin E showed no clear difference in stillbirth compared with placebo (moderate certainty).

• Vitamin supplementation for preventing miscarriage 2016 · Cochrane Headline outcomes only
  RR 1.31 [0.97, 1.76]
  7 studies · 21442 participants
  Moderate

SoF vitamin E vs placebo

• Non‐hormonal interventions for hot flushes in women with a history of breast cancer 2010 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 104 participants
  High

SoF vitamin E vs placebo

• Non‐hormonal interventions for hot flushes in women with a history of breast cancer 2010 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 104 participants
  High

Vitamin A vs placebo or usual care

Vitamin A supplementation leads to lower all‐cause mortality compared with placebo or usual care (high certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.88 [0.83, 0.93]
  19 studies · 1202382 participants
  High

Vitamin A vs placebo or usual care

Vitamin A supplementation probably leads to higher vomiting compared with placebo or usual care (moderate certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 1.97 [1.44, 2.69]
  4 studies · 10541 participants
  Moderate

Vitamin A vs placebo or usual care

Vitamin A supplementation leads to lower mortality due to diarrhoea compared with placebo or usual care (high certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.88 [0.79, 0.98]
  9 studies · 1098538 participants
  High

Vitamin A vs placebo or usual care

Vitamin A supplementation showed no clear difference in mortality due to measles compared with placebo or usual care (low certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.88 [0.69, 1.11]
  6 studies · 1088261 participants
  Low

Vitamin A vs placebo or usual care

Vitamin A supplementation showed no clear difference in mortality due to LRTI compared with placebo or usual care (low certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.98 [0.86, 1.12]
  9 studies · 1098538 participants
  Low

Vitamin A vs placebo or usual care

Vitamin A supplementation may leads to lower diarrhoea incidence Mean episodes per child per year compared with placebo or usual care (low certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.85 [0.82, 0.87]
  15 studies · 77946 participants
  Low

Vitamin A vs placebo or usual care

Vitamin A supplementation probably leads to lower measles incidence Mean episodes of measles per child per year compared with placebo or usual care (moderate certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.5 [0.37, 0.67]
  6 studies · 19566 participants
  Moderate

Vitamin A vs placebo or usual care

Vitamin A supplementation showed no clear difference in LRTI incidence Mean episodes per child per year compared with placebo or usual care (low certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.99 [0.92, 1.06]
  11 studies · 27540 participants
  Low

Vitamin A vs placebo or usual care

Vitamin A supplementation probably leads to lower bitot's spots incidence compared with placebo or usual care (moderate certainty).

• Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age 2022 · Cochrane Headline outcomes only
  RR 0.42 [0.33, 0.53]
  5 studies · 1063278 participants
  Moderate