Vitamin A

Zinc is required for vitamin A metabolism

Enhanced vitamin A utilization

⟡ Vitamin D3

Fat-soluble vitamins work together

Balanced fat-soluble vitamin status

Top studies from 40+ peer-reviewed papers

📚meta-analysisn=672

Bjelakovic G et al. • BMJ open (2024)

“Based on moderate certainty of evidence, vitamin A had no effect on mortality in the individually randomised trials.”

Key Findings:

Vitamin A did not reduce mortality in individually randomised trials (RR 0.99, 95% CI 0.93 to 1.05; I²=32%; p=0.19; 105 trials; moderate certainty), and this effect was not affected by the risk of bias.
In individually randomised trials, vitamin A had no effect on mortality in children (RR 0.96, 95% CI 0.88 to 1.04; I²=24%; p=0.28; 78 trials, 178 094 participants) nor in adults (RR 1.04, 95% CI 0.97 to 1.13; I²=24%; p=0.27; 27 trials, 61 880 participants).
Vitamin A reduced mortality in the cluster randomised trials (0.84, 95% CI 0.76 to 0.93; I²=66%; p=0.0008; 15 trials, 14 in children and 1 in adults; 364 343 participants; very low certainty).

📚meta-analysisn=451723

Oh C et al. • Nutrients (2020)

“In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.”

Key Findings:

IFA supplementation showed notable improvement in maternal anemia and the reduction in low birthweight, whereas LNS supplementation had no apparent effect on outcomes; further research that compares LNS and MMN supplementation could help understand differences with these commodities.
For single micronutrient supplementation, improvements were noted in only a few outcomes, mainly pre-eclampsia/eclampsia (calcium), maternal anemia (iron), preterm births (vitamin D), and maternal serum zinc concentration (zinc).
These findings highlight that micronutrient-specific supplementation should be tailored to specific groups or needs for maximum benefit.
In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.

📚meta-analysisn=6601

Wiysonge CS et al. • The Cochrane database of systematic reviews (2017)

“Antepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs.”

Key Findings:

Antepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs.
The intervention has largely been superseded by ART which is widely available and effective in preventing vertical transmission.
Further research warranted to confirm findings

📚meta-analysisn=909

Lodi G et al. • The Cochrane database of systematic reviews (2016)

“Surgical treatment for oral leukoplakia has not been assessed in an RCT that included a no treatment or placebo comparison.”

Key Findings:

Surgical treatment for oral leukoplakia has not been assessed in an RCT that included a no treatment or placebo comparison.
Nor has cessation of risk factors such as smoking been assessed.
The available evidence on medical and complementary interventions for treating people with leukoplakia is very limited.
We do not currently have evidence of a treatment that is effective for preventing the development of oral cancer.

📚meta-analysisn=8577

Compare with Others Find Based on Your Goals

Oliveira JM et al. • The Cochrane database of systematic reviews (2016)

“There was no evidence of benefit from different doses of vitamin A supplementation for postpartum women on maternal and infant mortality and morbidity, compared with other doses or placebo.”

Key Findings:

Effects were less certain at six months (risk ratio (RR) 0.50, 95% CI 0.09 to 2.71; 564 participants; 1 RCT; low-quality evidence).
We found insufficient evidence that vitamin A increases abdominal pain (RR 1.28, 95% CI 0.95 to 1.73; 786 participants; 1 RCT; low-quality evidence).
We found low-quality evidence that vitamin A supplementation increased breast milk retinol concentrations by 0.20 µmol/L at three to three and a half months (mean difference (MD) 0.20 µmol/L, 95% CI 0.08 to 0.31; 837 participants; 6 RCTs).
Infant: We did not find evidence that vitamin A supplementation reduced infant mortality at two to 12 months (RR 1.08, 95% CI 0.77 to 1.52; 6090 participants; 5 RCTs; low-quality evidence).

View all 40+ studies

What would you like to do next?

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Vitamin A

vitamin

Vitamin A (Retinol/Beta-Carotene)

Fat-soluble vitamin that maintains night vision, drives immune cell differentiation, and regulates skin turnover and cellular growth.

longevityvitaminessentialvisionimmune

40+ studies

Evidence

Reviewed 19 days ago

moderate

Safety

2500-5000 IU daily (retinol); up to 25000 IU (beta-carotene)

Dose

4-12 weeks

Time to Effect

Mixed carotenoids or low-dose retinyl palmitate

Best Form

Mechanisms of Action

👁️

Visual Function

Essential for rhodopsin production

🛡️

Immune Function

Maintains immune barriers and cell function

🧬

Gene Expression

Regulates cellular growth and differentiation

Biological PathwayBeta

How Vitamin A works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.

Supplement

Molecular Target

Biological Process

Health Outcome

Strong

Moderate

Emerging

strong

moderate

emerging

Tap node to isolate • Pinch to zoom • Tap edge for research

Recommended Dose

2500-5000 IU daily (retinol); up to 25000 IU (beta-carotene)

2500IU10000IU

Loading: Not required; avoid high doses

Optimal Timing

With fat-containing meal
Any time of day

Take with food

Available Forms

Form	Type
💊Mixed carotenoids or low-dose retinyl palmitate	Recommended
💊Beta-carotene (provitamin A)	Alternative
💊Retinyl acetate	Alternative
💧Cod liver oil	Alternative

Beta-carotene is safer (no toxicity risk) but conversion varies. Preformed vitamin A is more reliable but has toxicity potential.

Duration

Minimum: 4 weeks

Optimal: 12 weeks

Cycling: Not required

Note: Fat-soluble vitamin; requires dietary fat for absorption. Beta-carotene is safer as body regulates conversion.

👁️

Vision Support

Maintained night vision and eye health

⏱️ 2-4 weeks

80% of users notice thispositive

🛡️

Immune Support

Enhanced immune defenses

⏱️ 2-4 weeks

70% of users notice thispositive

✨

Skin Health

Improved skin cell turnover

⏱️ 4-8 weeks

65% of users notice thispositive

⚠️

Toxicity Risk

Fat-soluble; can accumulate to toxic levels

📅 With chronic excess

10% of users notice thistrade-off

ModerateMax safe dose: Max 3,000 IU/day PREFORMED vitamin A (retinol) in pregnancy. Beta-carotene unlimited - body regulates conversion.

🔴

Pregnant women

AVOID high-dose retinol; beta-carotene is safer

🔴

Smokers

Avoid high-dose beta-carotene supplements

Who Should NOT Take This

Pregnancy (high-dose retinol is teratogenic)
Liver disease

Drug Interactions

Retinoid medications (Accutane)severe

Do not combine; risk of vitamin A toxicity

Orlistatmild

May reduce absorption; take separately

isotretinoinsevere

Risk of vitamin A overdose, liver toxicity

Possible Side Effects

Hypervitaminosis A

severeuncommon

Tip: Stay below 10,000 IU/day preformed vitamin A

Skin yellowing (beta-carotene)

milduncommon

Tip: Harmless; reduce dose if concerned

Warnings

Preformed vitamin A can cause birth defects
Can accumulate to toxic levels
High-dose beta-carotene linked to lung cancer in smokers

⟡ Zinc

Zinc is required for vitamin A metabolism

Enhanced vitamin A utilization

⟡ Vitamin D3

Fat-soluble vitamins work together

Balanced fat-soluble vitamin status

Top studies from 40+ peer-reviewed papers

📚meta-analysisn=672

Bjelakovic G et al. • BMJ open (2024)

“Based on moderate certainty of evidence, vitamin A had no effect on mortality in the individually randomised trials.”

Key Findings:

Vitamin A did not reduce mortality in individually randomised trials (RR 0.99, 95% CI 0.93 to 1.05; I²=32%; p=0.19; 105 trials; moderate certainty), and this effect was not affected by the risk of bias.
In individually randomised trials, vitamin A had no effect on mortality in children (RR 0.96, 95% CI 0.88 to 1.04; I²=24%; p=0.28; 78 trials, 178 094 participants) nor in adults (RR 1.04, 95% CI 0.97 to 1.13; I²=24%; p=0.27; 27 trials, 61 880 participants).
Vitamin A reduced mortality in the cluster randomised trials (0.84, 95% CI 0.76 to 0.93; I²=66%; p=0.0008; 15 trials, 14 in children and 1 in adults; 364 343 participants; very low certainty).

📚meta-analysisn=451723

Oh C et al. • Nutrients (2020)

“In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.”

Key Findings:

IFA supplementation showed notable improvement in maternal anemia and the reduction in low birthweight, whereas LNS supplementation had no apparent effect on outcomes; further research that compares LNS and MMN supplementation could help understand differences with these commodities.
For single micronutrient supplementation, improvements were noted in only a few outcomes, mainly pre-eclampsia/eclampsia (calcium), maternal anemia (iron), preterm births (vitamin D), and maternal serum zinc concentration (zinc).
These findings highlight that micronutrient-specific supplementation should be tailored to specific groups or needs for maximum benefit.
In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.

📚meta-analysisn=6601

Wiysonge CS et al. • The Cochrane database of systematic reviews (2017)

“Antepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs.”

Key Findings:

Antepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs.
The intervention has largely been superseded by ART which is widely available and effective in preventing vertical transmission.
Further research warranted to confirm findings

📚meta-analysisn=909

Lodi G et al. • The Cochrane database of systematic reviews (2016)

“Surgical treatment for oral leukoplakia has not been assessed in an RCT that included a no treatment or placebo comparison.”

Key Findings:

Surgical treatment for oral leukoplakia has not been assessed in an RCT that included a no treatment or placebo comparison.
Nor has cessation of risk factors such as smoking been assessed.
The available evidence on medical and complementary interventions for treating people with leukoplakia is very limited.
We do not currently have evidence of a treatment that is effective for preventing the development of oral cancer.

📚meta-analysisn=8577

Compare with Others Find Based on Your Goals

Oliveira JM et al. • The Cochrane database of systematic reviews (2016)

“There was no evidence of benefit from different doses of vitamin A supplementation for postpartum women on maternal and infant mortality and morbidity, compared with other doses or placebo.”

Key Findings:

Effects were less certain at six months (risk ratio (RR) 0.50, 95% CI 0.09 to 2.71; 564 participants; 1 RCT; low-quality evidence).
We found insufficient evidence that vitamin A increases abdominal pain (RR 1.28, 95% CI 0.95 to 1.73; 786 participants; 1 RCT; low-quality evidence).
We found low-quality evidence that vitamin A supplementation increased breast milk retinol concentrations by 0.20 µmol/L at three to three and a half months (mean difference (MD) 0.20 µmol/L, 95% CI 0.08 to 0.31; 837 participants; 6 RCTs).
Infant: We did not find evidence that vitamin A supplementation reduced infant mortality at two to 12 months (RR 1.08, 95% CI 0.77 to 1.52; 6090 participants; 5 RCTs; low-quality evidence).

View all 40+ studies

What would you like to do next?

Related Supplements

E9.0

Vitamin E

9/10

Lipid-soluble antioxidant that shields cell membranes from oxidative damage — natural mixed tocopherols preferred over synthetic forms.

Bio8.5

Biotin

Cofactor for fatty acid synthesis and gluconeogenesis — strongest evidence for brittle nail syndrome and keratin infrastructure support.

Vc8.5

Vitamin C