Vitamin A for Pregnancy
Verdict: Published with Warning
Across 5 PubMed studies, the evidence for Vitamin A in Pregnancy grades Tier C — weak evidence. Effective, but with safety or population caveats.
C 🟠 C Weak Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.45
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
89%
Highly consistent evidence
Evidence level
E1
Cochrane high-quality SR/MA
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.448
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (3 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (5)L2 · primary research & systematic reviews
Vitamin A supplementation during pregnancy for maternal and newborn outcomes
Finding: Across 19 RCTs (>310,000 women), antenatal vitamin A had no effect on maternal mortality (RR 0.88, 95% CI 0.65-1.20), perinatal mortality (RR 1.01, 95% CI 0.95-1.07) or preterm birth (RR 0.98, 95% CI 0.94-1.01), but reduced maternal night blindness (RR 0.79, 95% CI 0.64-0.98) and anaemia (RR 0.64, 95% CI 0.43-0.94) in deficiency-endemic populations.
View on PubMed Effect of vitamin A supplementation in women of reproductive age on maternal survival in Ghana (ObaapaVitA): a cluster-randomised, placebo-controlled trial
Finding: In 207,781 women (weekly 25,000 IU retinol vs placebo), vitamin A did not reduce pregnancy-related mortality (adjusted OR 0.92, 95% CI 0.73-1.17, p=0.51) or all-cause female mortality (adjusted rate ratio 1.01, 95% CI 0.93-1.09, p=0.85).
View on PubMed Vitamin A and carotenoids during pregnancy and maternal, neonatal and infant health outcomes: a systematic review and meta-analysis
Finding: Pooling 23 trials (17 in meta-analysis), vitamin A/beta-carotene had no significant effect on pregnancy-related maternal mortality (RR 0.86, 95% CI 0.60-1.24, I2=74%), birthweight, preterm birth or stillbirth, but reduced maternal anaemia (RR 0.81, 95% CI 0.69-0.94) and showed a possible signal of increased mother-to-child HIV transmission.
View on PubMed Vitamin A Supplementation during Pregnancy in Shaping Child Growth Outcomes: A Meta-analysis
Finding: Across 55 RCT+observational studies (426,098 pregnancies), vitamin A was associated with reduced preterm birth (9% in healthy-mother RCTs, P<0.001) and reduced low birthweight (24% in complicated-mother RCTs, P=0.032) with no effect of dose and no harm up to 4000 mcg RAE/day, but findings rest on growth surrogates and pool observational data so overstate benefit relative to mortality-anchored Cochrane evidence.
View on PubMed Impact of Vitamin A Supplementation on Pregnant Women and on Women Who Have Just Given Birth: A Systematic Review
Finding: This narrative systematic review (no pooled effect estimate) reported that supplementation increased maternal liver vitamin A stores, improved immune function and reduced gestational night blindness, but found no change in outcomes at childbirth or in maternal, fetal and child mortality.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Supportive
Vitamin A — GRAS — 21 CFR 184.1245, 184.1930 — Technical Effect: NUTRIENT SUPPLEMENT — SCOGS no. 118 source↗
L4b EU EFSA
Neutral
Vitamin A contributes to the normal function of the immune system; Vitamin A contributes to the maintenance of normal vision; Vitamin A contributes to the maintenance of normal skin; Vitamin A contributes to the maintenance of normal mucous membranes; Vitamin A has a role in the process of cell specialisation; Vitamin A contributes to normal iron metabolism. source↗
L4c UK NHS
Cautious
Do not take cod liver oil or any supplements containing vitamin A (retinol) when you're pregnant. Too much vitamin A could harm your baby. source↗
L4d TW TFDA / 衛福部
Neutral
維生素A 指示藥每日用量上限 10,000 IU（3,000 微克 RE）；換算：1 微克 RE = 1 微克 Retinol = 6 微克 β-Carotene；3 微克 RE = 10 IU。 source↗
L4e WHO
Supportive
In settings where vitamin A deficiency is a public health problem, vitamin A supplementation is recommended in infants and children 6-59 months of age as a public health intervention to reduce child morbidity and mortality (strong recommendation). source↗
L5a NIH Office of Dietary Supplements
Supportive
The most common clinical sign of vitamin A deficiency is xerophthalmia, which develops after plasma retinol has been low. The first sign is night blindness, or the inability to see in low light or darkness as a result of low rhodopsin levels in the retina. source↗
L5b Mayo Clinic
Cautious
If you are or might become pregnant, talk with your healthcare professional before taking vitamin A. The use of too many vitamin A supplements during pregnancy has been linked to birth defects. More specifically, an excessive intake of vitamin A, defined as more than 10,000 IU of vitamin A per day, may be associated with fetal malformations of the bones, urinary tract or nervous system. source↗
L5c Cleveland Clinic
Cautious
Vitamin A is teratogenic, which means it can cause fetal development issues. Women who are pregnant or planning a pregnancy shouldn't take excessive doses of vitamin A. Once those malformations occur, they can't be reversed. For all adults, the Tolerable Upper Intake Level (UL) — the most vitamin A one can take without experiencing negative health effects — is 3,000 mcg RAE, or 10,000 IU. source↗
L5d Harvard Health
Cautious
Avoid excessive vitamins before conception. Too much vitamin A, for example, can be bad for a developing fetus. source↗
L5e Specialty Society (condition-mapped)
Cautious
Vitamin A supplementation is only recommended for pregnant women in areas where vitamin A deficiency is a severe public health problem, to prevent night blindness. Current evidence indicates that vitamin A supplementation during pregnancy does not reduce the risk of illness or death in mothers or their infants. Pregnant women should be encouraged to receive adequate nutrition, which is best ach… source↗