Vitamin A
Vitamin A is essential for vision and immune function. Supplemental benefit depends strongly on baseline status and dose.
Overview
What is vitamin A?
Vitamin A is a fat soluble vitamin required for optimal skin health and immunity. Vitamin A includes fat-soluble metabolites like retinols, retinals, retinyl esters, retinoic acids, and provitamin A carotenoids such as beta-carotene. These compounds support vision, immune function, bone metabolism, and cell growth. Vitamin A is stored mainly in the liver and obtained from animal products and plant-based provitamin A sources.
Dosage
The recommended dietary allowance (RDA) of vitamin A is 900 mcg/day for men and 700 mcg/day for women.
Effect graph
Effect heatmap
SupplementDEX Database
63 conditions for , and rated at least stars. All purchase bands. No minimum star filter.
Database Snapshot
Most vitamin a research is concentrated in a handful of conditions.
- All-cause mortality accounts for 9 of 141 studies (6%).
- Bronchopulmonary dysplasia accounts for 9 of 141 studies (6%).
- Skin wrinkles accounts for 8 of 141 studies (6%).
- Sparse coverage remains for Atopy, Autism spectrum disorder, Cervical cancer.
Dietary Sources
Top dietary sources
Ranked by amount per 100 g
- 961 mcg100 g
- 852 mcg100 g
- 757 mcg100 g
- 558 mcg100 g
- 524 mcg100 g
- 436 mcg100 g
- 169 mcg100 g
- 147 mcg100 g
Safety
Oral vitamin A is likely safe when used in daily doses below the tolerable upper intake level of 10,000 IU (3000 mcg). Vitamin A supplementation is associated with an increased risk of mortality.
Frequently Asked Questions
References
Sources122 references
SupplementDEX uses only high-quality sources to determine supplement effectiveness.
SupplementDEX Database · Vitamin A deficiency
5 references1.SupplementDEX Database: Vitamin A deficiency — Changes in Vitamin A Levels and the Effect of Early Vitamin A Supplementation on Vitamin A Levels in Infants Throughout the First 6 Months of Life: A Prospective Cohort Study in Chongqing, China2021
An observational study of 1016 children/adolescents found that results: Infant VA levels increased significantly from 0.499 ± 0.146 to 1.061 ± 0.414 μmol/L with age at 6 months, even without VA supplementation ( P P > 0.05).
2.SupplementDEX Database: Vitamin A deficiency — Vitamin A supplementation every 6 months with retinol in 1 million pre-school children in north India: DEVTA, a cluster-randomised trial2013
The DEVTA cluster RCT in ~1 million Indian preschool children found 6-monthly vitamin A did not reduce mortality (RR 0.96, 95% CI 0.89–1.03), though pooled analysis with prior trials suggested an 11% mortality reduction.
3.SupplementDEX Database: Vitamin A deficiency — Vitamin A deficiency and xerophthalmia among school-aged children in Southeastern Asia2004
A meta-analysis found that the estimated prevalence of VA deficiency is 23.4%, suggesting that there are approximately 83 million VA-deficient school-aged children in the region, of whom 10.9% (9 million, at an overall prevalence of 2.6%) have mild xerophthalmia (night blindness or Bitot's spot).
4.SupplementDEX Database: Vitamin A deficiency — Chronic low intakes of vitamin A-rich foods in households with xerophthalmic children: a case-control study in Nepal1996
An observational study in children/adolescents found that cases were less likely to consume preformed vitamin A-rich foods throughout the year [odds ratio (OR) = 1.2-4.5] with the strongest differences observed from October to December (OR = 2.0-4.2).
5.SupplementDEX Database: Vitamin A deficiency — Prevalence of xerophthalmia and efficacy of vitamin A prophylaxis in preventing xerophthalmia co-existing with malnutrition in rural Indian children1993
A study of 4302 children/adolescents found that the ability of vitamin A prophylaxis to curb xerophthalmia was greatest at the extreme ends of the nutritional grade spectrum.
SupplementDEX Database · Aging skin
6 references6.SupplementDEX Database: Aging skin — Efficacy and Tolerability of a Retinoid Eye Cream for Fine to Moderate Wrinkles of the Periorbital Region2022
A 12-week open-label study of 26 adults (ages 35–65) found nightly retinoid eye cream significantly improved periorbital wrinkles, texture, and under-eye puffiness by week 12 without related adverse events.
7.SupplementDEX Database: Aging skin — Randomized parallel control trial checking the efficacy and impact of two concentrations of retinol in the original formula on the aging skin condition: Pilot study2020
An 8-week pilot RCT of 40 adults applying retinol 0.15% on one side and 0.3% on the other found both concentrations improved skin condition and wrinkles with minimal irritation and no significant between-side differences.
8.SupplementDEX Database: Aging skin — A Clinical Anti-Ageing Comparative Study of 0.3 and 0.5% Retinol Serums: A Clinically Controlled Trial2020
A 12-week study of 37 volunteers found retinol serums at 0.3% and 0.5% reduced hyperpigmentation, wrinkles, and skin roughness, with more irritation on the 0.5% side.
9.SupplementDEX Database: Aging skin — Efficacy and Tolerability of a Skin Brightening/Anti-Aging Cosmeceutical Containing Retinol 0.5%, Niacinamide, Hexylresorcinol, and Resveratrol2016
A 10-week open-label study of 25 adults (mean age 53) using a cosmeceutical with 0.5% retinol plus niacinamide, resveratrol, and hexylresorcinol found significant improvements in fine lines, hyperpigmentation, and smoothness.
10.SupplementDEX Database: Aging skin — Improvement of photoaged facial skin in middle-aged Japanese females by topical retinol (vitamin A alcohol): a vehicle-controlled, double-blind study2009
A 26-week double-blind study of 57 middle-aged Japanese women found 0.075% retinol cream improved fine wrinkles in 50% and deep wrinkles in 28% of treated sides versus 24% and 2% with vehicle.
11.SupplementDEX Database: Aging skin — Improvement of naturally aged skin with vitamin A (retinol)2007
A 24-week RCT of 36 elderly adults (mean age 87) found topical 0.4% retinol improved fine wrinkling scores and increased dermal glycosaminoglycans and procollagen I versus vehicle on treated arms.
SupplementDEX Database · All-cause mortality
8 references12.SupplementDEX Database: All-cause mortality — Effects of primary or secondary prevention with vitamin A supplementation on clinically important outcomes: a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis2024
A systematic review of 120 RCTs (1.67 million participants) found vitamin A did not reduce mortality in individually randomized trials (RR 0.99) but showed reduced mortality in cluster trials (RR 0.84, very low certainty).
13.SupplementDEX Database: All-cause mortality — Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age2022
A Cochrane meta-analysis of 47 trials (~1.22 million children ages 6–59 months) found vitamin A supplementation reduced all-cause mortality by 12% (RR 0.88, 95% CI 0.83–0.93) and diarrhoea mortality by 12% versus control.
14.SupplementDEX Database: All-cause mortality — Should universal distribution of high dose vitamin A to children cease?2018
An editorial asking whether universal high-dose vitamin A distribution to children should cease was identified, but the available abstract contained insufficient detail to report specific outcomes.
15.SupplementDEX Database: All-cause mortality — Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age2017
A 2017 Cochrane meta-analysis of 47 trials (~1.22 million children) found vitamin A reduced all-cause mortality by 12% (RR 0.88, 95% CI 0.83–0.93) and diarrhoea incidence (RR 0.85) in children ages 6–59 months.
16.SupplementDEX Database: All-cause mortality — Meta-regression analyses, meta-analyses, and trial sequential analyses of the effects of supplementation with beta-carotene, vitamin A, and vitamin E singly or in different combinations on all-cause mortality: do we have evidence for lack of harm?2013
A meta-analysis of 53 low-bias trials (241,883 adults) found beta-carotene above 9.6 mg/day increased mortality (RR 1.06) and vitamin E above 15 mg/day increased mortality (RR 1.03), while vitamin A above 800 µg showed no significant effect.
17.SupplementDEX Database: All-cause mortality — Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases2012
A meta-analysis of 78 antioxidant trials (296,707 participants) found no overall mortality effect (RR 1.02), but low-bias trials showed increased mortality with beta-carotene (RR 1.05) and vitamin E (RR 1.03).
18.SupplementDEX Database: All-cause mortality — Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis2011
A meta-analysis of 43 trials found vitamin A supplementation in children under 5 reduced all-cause mortality by 24% (RR 0.76), diarrhoea mortality by 28%, and measles incidence (RR 0.50).
19.SupplementDEX Database: All-cause mortality — Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis2007
A meta-analysis of 68 antioxidant trials (232,606 participants) found no overall mortality benefit; high-bias trials suggested possible harm with beta-carotene, vitamin A, and vitamin E.
SupplementDEX Database · Measles
2 references20.SupplementDEX Database: Measles — Effectiveness of measles vaccination and vitamin A treatment2010
A meta-analysis found that a meta-analysis of these studies found that vaccination was 85% [95% confidence interval (CI) 83-87] effective in preventing measles disease, which will be used as a proxy for measles mortality in LiST for countries vaccinating before one year of age.
21.SupplementDEX Database: Measles — Vitamin A for treating measles in children2005
A meta-analysis found that 100000 IU/day there was a reduction in the incidence of croup (RR 0.53; 95% CI 0.29 to 0.89) but no significant reduction in the incidence of pneumonia (RR 0.92; 95% CI 0.69 to 1.22) or diarrhoea (RR 0.80; 95% CI 0.27 to 2.34) with two doses.
SupplementDEX Database · Multiple sclerosis
1 reference22.SupplementDEX Database: Multiple sclerosis — Effect of Vitamin A Supplementation on fatigue and depression in Multiple Sclerosis patients: A Double-Blind Placebo-Controlled Clinical Trial2016
A randomized trial in patients with depression found that 25000 IU/day for 6 months vitamin A supplementation helped during interferon therapy in the treatment process and improved psychiatric outcomes for anti-inflammatory mechanisms.
SupplementDEX Database · Oral leukoplakia
2 references23.SupplementDEX Database: Oral leukoplakia — Response of oral leukoplakias to the administration of vitamin A1998
A randomized trial of 33 found that 200000 IU/day for 6 months their cancer-causing habit, which can be quantitated (an average of 13.1 betel quids/day, 26.1 min/quid), did not change during the trial period.
24.SupplementDEX Database: Oral leukoplakia — Chemoprevention of oral leukoplakia with vitamin A and beta carotene: an assessment1997
A randomized trial of 55 women found that 300000 IU/day the results of this study, as well as those from previous studies, appear to provide strong supporting evidence to justify long term trials with vitamin A in subjects with high-risk leukoplakias with oral cancer as an endpoint.
25.SupplementDEX Database: Postpartum complications — Vitamin A or beta-carotene supplementation reduces symptoms of illness in pregnant and lactating Nepali women2000
A randomized trial in women found that among women receiving vitamin A, the total number of days of illness symptoms accrued over the last 12 wk of pregnancy was lower by 5 d compared with the placebo recipients.
26.SupplementDEX Database: Postpartum complications — Double blind, cluster randomised trial of low dose supplementation with vitamin A or beta carotene on mortality related to pregnancy in Nepal. The NNIPS-2 Study Group1999
A randomized trial in women found that 7,000 µg retinol equivalents/week combined, vitamin A or beta carotene lowered mortality by 44% (0.56 (0.37 to 0.84), P<0.005) and reduced the maternal mortality ratio from 645 to 385 deaths per 100 000 live births, or by 40% (P<0.02).
SupplementDEX Database · Retinitis pigmentosa
3 references27.SupplementDEX Database: Retinitis pigmentosa — Vitamin A and fish oils for preventing the progression of retinitis pigmentosa2020
A meta-analysis of 944 participants found that we included randomized controlled trials that enrolled participants of any age diagnosed with any degree of severity or type of RP, and evaluated the effectiveness of vitamin A, fish oils (DHA), or both compared to placebo, vitamins (other than vitamin A), or no therapy, as a.
28.SupplementDEX Database: Retinitis pigmentosa — Association of Vitamin A Supplementation With Disease Course in Children With Retinitis Pigmentosa2018
An observational study of 55 adults found that the adjusted model confirmed a slower mean rate of decline in the vitamin A cohort (difference, 0.0771 loge-unit per year; 95% CI for the difference, 0.0191-0.1350 loge-unit per year; P = .009).
29.SupplementDEX Database: Retinitis pigmentosa — A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa1993
A randomized trial of 601 adults found that 15000 IU/day for 4–6 years while not statistically significant, similar trends were observed for rates of decline of visual field area.
SupplementDEX Database · Skin wrinkles
7 references30.SupplementDEX Database: Skin wrinkles — Efficacy and Tolerability of Topical 0.1% Stabilized Bioactive Retinol for Photoaging: A Vehicle-Controlled Integrated Analysis2024
A study of 5 women found that this pooled analysis of 6 vehicle-controlled clinical studies provides new evidence for the efficacy of 0.1% stabilized bioactive retinol in improving signs of photoaging without causing major irritation.
31.SupplementDEX Database: Skin wrinkles — A Double-Blind, Comparative Clinical Study of Newly Formulated Retinol Serums vs Tretinoin Cream in Escalating Doses: A Method for Rapid Retinization With Minimized Irritation2020
A randomized trial found that retinol serum (0.25%, 0.5%, 1.0%) was safe and effective with equivalent/or better performance and tolerability than tretinoin creams.
32.SupplementDEX Database: Skin wrinkles — A randomized, double-blind, controlled comparative trial of the anti-aging properties of non-prescription tri-retinol 1.1% vs. prescription tretinoin 0.025%2012
A randomized trial found that there were no significant differences in efficacy between the two products for these assessments.
33.SupplementDEX Database: Skin wrinkles — Two concentrations of topical tretinoin (retinoic acid) cause similar improvement of photoaging but different degrees of irritation. A double-blind, vehicle-controlled comparison of 0.1% and 0.025% tretinoin creams1995
A randomized trial of 35 patients with photoaging found that both 0.1% and 0.025% tretinoin produced statistically significant overall improvement in photoaging of the face compared with vehicle; there were no clinically or statistically significant differences in efficacy between the two concentrations of tretinoin.
34.SupplementDEX Database: Skin wrinkles — Topical tretinoin (retinoic acid) treatment of hyperpigmented lesions associated with photoaging in Chinese and Japanese patients: a vehicle-controlled trial1994
A randomized trial found that at the end of treatment, hyperpigmented lesions of the face and hands were lighter or much lighter in 90% of patients receiving tretinoin compared with 33% receiving vehicle (p < 0.0001).
35.SupplementDEX Database: Skin wrinkles — Topical tretinoin for treatment of photodamaged skin. A multicenter study1991
A randomized trial of 251 found that seventy-nine percent of the subjects who received 0.05% tretinoin for 24 weeks showed overall improvement in photodamaged skin compared with improvement in 48% of the vehicle-treated control subjects.
36.SupplementDEX Database: Skin wrinkles — Topical tretinoin improves photoaged skin. A double-blind vehicle-controlled study1988
A randomized trial of 30 found that fourteen of the 15 patients who received tretinoin to the face had improvement in photoaging, whereas none of the vehicle-treated patients' faces improved, a statistically significant difference in response between the two groups.
SupplementDEX Database · Ulcerative colitis
1 reference37.SupplementDEX Database: Ulcerative colitis — Vitamin A supplementation decreases disease activity index in patients with ulcerative colitis: A randomized controlled clinical trial2018
A randomized trial of 50 uc patients found that 000 IU/day the NNT [95%CI] values for the clinical response was 3 [2-40] and for the mucosal healing was 5 [2.90-10.4].
SupplementDEX Database · Atopy
2 references38.SupplementDEX Database: Atopy — Vitamin A supplementation and BCG vaccination at birth may affect atopy in childhood: long-term follow-up of a randomized controlled trial2013
A long-term follow-up of a birth RCT in Guinea-Bissau found neonatal vitamin A was associated with increased atopy (OR 2.88) and wheeze, especially when combined with BCG vaccination.
39.SupplementDEX Database: Atopy — Vitamin A supplementation and risk of atopy: long-term follow-up of a randomized trial of vitamin A supplementation at six and nine months of age2013
A 7-year follow-up of 263 Guinean children found vitamin A given at 6 and 9 months did not significantly affect atopy risk at age 7 (prevalence ratio 1.23, 95% CI 0.69–2.18).
40.SupplementDEX Database: Intestinal parasite infection — Does vitamin A supplementation protect schoolchildren from acquiring soil-transmitted helminthiasis? A randomized controlled trial2014
A randomized trial of 214 children/adolescents found that 200000 IU/day there were no significant differences in the reinfection rates and intensities of STH between vitamin A supplemented-children and those who received placebo at 3 and 6 months (p > 0.05).
SupplementDEX Database · Melanoma
1 reference41.SupplementDEX Database: Melanoma — Randomized trial of vitamin A versus observation as adjuvant therapy in high-risk primary malignant melanoma: a Southwest Oncology Group study1994
A randomized trial of 48 found that 100000 IU/day for 18 months there was no difference in disease-free survival or overall survival between the two groups.
SupplementDEX Database · Miscarriage
1 reference42.SupplementDEX Database: Miscarriage — Vitamin supplementation for preventing miscarriage2016
A meta-analysis of 276820 participants found that multivitamin supplementation There was evidence of a decrease in the risk for stillbirth among women receiving multivitamins plus iron and folic acid compared iron and folate only groups (RR 0.92, 95% CI 0.85 to 0.99, 10 trials, 79,851 women; high-quality evidence).
SupplementDEX Database · Sepsis
1 reference43.SupplementDEX Database: Sepsis — Enteral Low-Dose Vitamin A Supplementation in Preterm or Low Birth Weight Infants to Prevent Morbidity and Mortality: a Systematic Review and Meta-analysis2022
A meta-analysis of 4 trials (800 very low birth weight infants) found low-dose enteral vitamin A increased serum retinol but had no effect on mortality, sepsis, BPD, or hospital stay.
SupplementDEX Database · Tuberculosis
3 references44.SupplementDEX Database: Tuberculosis — Effects of zinc and vitamin A supplementation on prognostic markers and treatment outcomes of adults with pulmonary tuberculosis: a systematic review and meta-analysis2022
A meta-analysis of 1375 participants found that among adults with pulmonary TB, zinc (RR: 0.94, 95% CI: 0.86 to 1.03), vitamin A (RR: 0.90, 95% CI: 0.80 to 1.01) and combined zinc and vitamin A (RR: 0.98, 95% CI: 0.89 to 1.08) supplementation were not significantly associated with TB treatment success.
45.SupplementDEX Database: Tuberculosis — Adjunctive vitamin A and D during pulmonary tuberculosis treatment: a randomized controlled trial with a 2 × 2 factorial design2020
A randomized trial of 761 patients with positive baseline sputum smear results found that 2000 IU/day the allocation to vitamin A or D did not significantly influence the time to sputum smear conversion [vitamin A: adjusted hazard ratio: 1.021, 95% CI: (0.821, 1.271); vitamin D: adjusted hazard ratio: 0.949, 95% CI: (0.760, 1.185)].
46.SupplementDEX Database: Tuberculosis — Nutritional supplements for people being treated for active tuberculosis2011
A meta-analysis of 6842 participants found that results are presented as risk ratios (RR) for dichotomous variables, and mean differences (MD) for continuous variables, with 95% confidence intervals (CI).
47.SupplementDEX Database: Bronchopulmonary dysplasia — The Relationship of Vitamin A and Neonatal Respiratory Diseases: A Meta-Analysis2024
A meta-analysis of 24 studies found vitamin A deficiency was associated with higher neonatal respiratory disease risk (OR 4.86), while vitamin A supplementation improved outcomes for NRDS and bronchopulmonary dysplasia.
48.SupplementDEX Database: Bronchopulmonary dysplasia — Oral vitamin A supplementation in preterm infants to improve health outcomes: A systematic review and meta-analysis2022
A meta-analysis of 4 RCTs (800 preterm infants) found oral vitamin A did not reduce mechanical ventilation duration or BPD at 36 weeks but shortened noninvasive ventilation by about 1 day.
49.SupplementDEX Database: Bronchopulmonary dysplasia — Vitamin A supplementation prevents the bronchopulmonary dysplasia in premature infants: A systematic review and meta-analysis2021
A meta-analysis of 9 RCTs (1,409 preterm infants) found vitamin A supplementation reduced BPD incidence (OR 0.67, 95% CI 0.52–0.88) without affecting mortality, ROP, or NEC.
50.SupplementDEX Database: Bronchopulmonary dysplasia — Should Vitamin A Injections to Prevent Bronchopulmonary Dysplasia or Death Be Reserved for High-Risk Infants? Reanalysis of the National Institute of Child Health and Human Development Neonatal Research Network Randomized Trial2021
A reanalysis of the NICHD vitamin A trial (807 infants) found treatment benefit for BPD or death was greater in lower-risk infants (25% predicted risk: RR 0.73) than higher-risk infants (75% risk: RR 0.96).
51.SupplementDEX Database: Bronchopulmonary dysplasia — Vitamin A supplementation for extremely-low-birth-weight infants. National Institute of Child Health and Human Development Neonatal Research Network1999
An RCT of 807 extremely low birth weight infants found intramuscular vitamin A 5000 IU three times weekly for 4 weeks reduced BPD or death at 36 weeks (55% vs 62%, RR 0.89) with 1 additional survivor without BPD per 14–15 treated infants.
52.SupplementDEX Database: Bronchopulmonary dysplasia — Vitamin A to prevent bronchopulmonary dysplasia in very-low-birth-weight infants: has the dose been too low? The NICHD Neonatal Research Network1997
A pilot dose-finding study of 91 VLBW infants found 5000 IU vitamin A three times weekly achieved target serum retinol levels, whereas lower doses did not, with no clinical toxicity observed.
53.SupplementDEX Database: Bronchopulmonary dysplasia — Trial of vitamin A supplementation in very low birth weight infants at risk for bronchopulmonary dysplasia1992
An RCT of 49 VLBW infants found intramuscular retinyl palmitate 2000 IU every other day did not reduce BPD incidence (48% vs 55%) compared with placebo.
54.SupplementDEX Database: Bronchopulmonary dysplasia — Clinical trial of vitamin A supplementation in infants susceptible to bronchopulmonary dysplasia1987
An RCT of 40 VLBW neonates found vitamin A 2000 IU every other day for 28 days reduced BPD (9/20 vs 17/20, P<0.008) and mechanical ventilation need at day 28.
55.SupplementDEX Database: Head and neck cancer — EUROSCAN, a randomized trial of vitamin A and N-acetylcysteine in patients with head and neck cancer or lung cancer. For the EUropean Organization for Research and Treatment of Cancer Head and Neck and Lung Cancer Cooperative Groups2000
The EUROSCAN RCT of 2,592 head-and-neck cancer patients found vitamin A plus NAC did not improve survival or reduce second primary tumors.
56.SupplementDEX Database: Lower respiratory infection — Impact of Maternal Daily Oral Low-Dose Vitamin A Supplementation on the Mother-Infant Pair: A Randomised Placebo-Controlled Trial in China2021
An RCT of 245 lactating Chinese women found daily low-dose vitamin A 1800 IU for 2 months improved maternal serum retinol and slowed the decline in breast milk retinol but did not reduce infant febrile illness or eczema.
57.SupplementDEX Database: Lower respiratory infection — Vitamin A for preventing acute lower respiratory tract infections in children up to seven years of age2008
A meta-analysis found that two studies reported that vitamin A significantly reduced the incidence of acute LRTI with children with poor nutritional status or weight, but increased it in normal children.
58.SupplementDEX Database: Lower respiratory infection — Vitamin A supplementation and childhood morbidity from diarrhea and respiratory infections: a meta-analysis2003
A meta-analysis found that the combined results indicated that vitamin A supplementation has no consistent overall protective effect on the incidence of diarrhea (relative risk, 1.00; 95% CI, 0.94-1.07) and that it slightly increases the incidence of respiratory tract infections (relative risk, 1.08;.
SupplementDEX Database · Pneumonia
5 references59.SupplementDEX Database: Pneumonia — Vitamin A in children's pneumonia for a COVID-19 perspective: A systematic review and meta-analysis of 15 trials2022
A meta-analysis of 3496 participants found that the Meta-analysis showed that vitamin A combined with conventional therapy improved clinical efficacy (P .05).
60.SupplementDEX Database: Pneumonia — Vitamin A supplementation for prophylaxis or therapy in childhood pneumonia: a systematic review of randomized controlled trials2010
A systematic review found that vitamin A supplementation for prophylaxis or therapy in childhood pneumonia: a systematic review of randomized controlled trials..
61.SupplementDEX Database: Pneumonia — Vitamin A for non-measles pneumonia in children2005
A meta-analysis of 1453 participants found that there was no significant reduction in the mortality associated with pneumonia in children treated with vitamin A compared to those who were not (pooled odds ratio (OR) 1.49; 95% confidence interval (CI) 0.66 to 3.35).
62.SupplementDEX Database: Pneumonia — Vitamin A supplementation and severity of pneumonia in children admitted to the hospital in Dar es Salaam, Tanzania1998
A randomized trial of 341 children/adolescents found that 200,000 IU (>1 y) or 100,000 IU (infants), 2 doses of the 346 children in the vitamin A group, 13 died in the hospital, compared with 8 of 341 children in the placebo group; the relative mortality was 1.63 (95% CI: 0.67, 3.97; P = 0.28).
63.SupplementDEX Database: Pneumonia — Potential interventions for the prevention of childhood pneumonia in developing countries: a meta-analysis of data from field trials to assess the impact of vitamin A supplementation on pneumonia morbidity and mortality. The Vitamin A and Pneumonia Working Group1995
A meta-analysis found that the mortality reduction in the 6-11 month age group was consistent with that observed for older age groups (RR = 0.69; 95% CI = 0.54, 0.90), but there was no reduction for 0-5 month-olds (RR = 0.97; 95% CI = 0.73, 1.29).
SupplementDEX Database · Oral health
1 reference64.SupplementDEX Database: Oral health — Evaluating the Protective Role of Vitamin A Supplementation in Periodontal Health: A Comprehensive Systematic Review and Meta-Analysis2024
A meta-analysis of 50722 participants found that the meta-analysis revealed a pooled odds ratio (OR) of 0.97 (95% CI: 0.94-1.00) for the association between vitamin A supplementation and periodontal health, indicating a slight protective effect.
SupplementDEX Database · Acne
1 reference65.SupplementDEX Database: Acne — A Topical Combination Regimen of Benzoyl Peroxide and Retinol Moisturizer for Mild to Moderate Acne2022
A study of 33 adults with mild-to-moderate acne found morning 2.5% benzoyl peroxide plus evening topical retinol for 12 weeks significantly reduced total acne lesions and improved skin appearance.
66.SupplementDEX Database: Alcohol-related liver disease — A randomized trial of antioxidant therapy alone or with corticosteroids in acute alcoholic hepatitis2007
A 6-month RCT of 70 patients with severe alcoholic hepatitis found antioxidant therapy including vitamin A, with or without corticosteroids, did not improve 180-day survival (52.8% vs 55.8%, P=0.699).
SupplementDEX Database · Asthma
1 reference67.SupplementDEX Database: Asthma — Dietary intake of vitamin A, lung function and incident asthma in childhood2021
A prospective cohort in the Avon Longitudinal Study found higher preformed vitamin A intake at age 7 was associated with better lung function and lower incident asthma risk at age 15, but not β-carotene.
68.SupplementDEX Database: Autism spectrum disorder — A weekly vitamin A supplementary program alleviates social impairment in Chinese children with autism spectrum disorders and vitamin A deficiency2021
A 6-month study of 138 Chinese children with ASD and vitamin A deficiency found weekly-dose vitamin A improved serum retinol and reduced social impairment scores more than standard daily supplementation.
69.SupplementDEX Database: Autism spectrum disorder — Vitamin A improves the symptoms of autism spectrum disorders and decreases 5-hydroxytryptamine (5-HT): A pilot study2018
A pilot study in children with autism spectrum disorder found vitamin A supplementation improved behavioral symptoms and reduced elevated serum 5-hydroxytryptamine levels.
SupplementDEX Database · Breast cancer
3 references70.SupplementDEX Database: Breast cancer — Dietary Vitamin A Intake and Circulating Vitamin A Concentrations and the Risk of Three Common Cancers in Women: A Meta-Analysis2022
A meta-analysis of 49 studies found higher dietary vitamin A intake was associated with lower breast, ovarian, and cervical cancer risk in women (pooled OR 0.83 for diet/supplements), but circulating vitamin A showed no significant association.
71.SupplementDEX Database: Breast cancer — Retinol, vitamins A, C, and E and breast cancer risk: a meta-analysis and meta-regression2011
A meta-analysis of 51 studies found total vitamin A intake reduced breast cancer risk by 17% (pooled OR 0.83), though retinol and vitamin E associations became nonsignificant in cohort-only subgroup analyses.
72.SupplementDEX Database: Breast cancer — Dietary carotenoids and vitamins A, C, and E and risk of breast cancer1999
A prospective cohort of 83,234 women in the Nurses' Health Study found higher α-carotene, β-carotene, and vitamin C intake were inversely associated with premenopausal breast cancer risk, especially with family history.
SupplementDEX Database · Cataracts
4 references73.SupplementDEX Database: Cataracts — Smoking, dietary factors and major age-related eye disorders: an umbrella review of systematic reviews and meta-analyses2023
An umbrella review found smoking and dietary factors including carotenoids have varying evidence strength for cataract, glaucoma, AMD, and diabetic retinopathy.
74.SupplementDEX Database: Cataracts — Association of vitamin A and β-carotene with risk for age-related cataract: a meta-analysis2014
A meta-analysis found higher vitamin A and β-carotene intake were inversely associated with cataract risk (RR 0.83 for intake; RR 0.765 for serum vitamin A after sensitivity analysis).
75.SupplementDEX Database: Cataracts — Association of blood antioxidants and vitamins with risk of age-related cataract: a meta-analysis of observational studies2013
A meta-analysis of 13 observational studies (18,999 participants) found higher blood lutein (OR 0.75) and zeaxanthin (OR 0.70) were inversely associated with age-related cataract risk.
76.SupplementDEX Database: Cataracts — Diet and cataract: the Blue Mountains Eye Study2000
The Blue Mountains Eye Study of 2,900 adults (ages 49–97) found higher protein, vitamin A, niacin, thiamin, and riboflavin intake were associated with reduced nuclear cataract prevalence.
SupplementDEX Database · Cervical cancer
1 reference77.SupplementDEX Database: Cervical cancer — Vitamin A and risk of cervical cancer: a meta-analysis2012
A meta-analysis of 11 studies (12,136 participants) found total vitamin A intake (OR 0.59) and blood vitamin A (OR 0.60) were inversely associated with cervical cancer risk.
78.SupplementDEX Database: Chemotherapy-induced diarrhea — Mucosal pathology of the upper gastrointestinal tract associated with intensive chemotherapy in children: vitamin A supplements do not prevent lesions2002
An RCT of 20 children on intensive chemotherapy found two-thirds developed upper GI mucosal lesions and vitamin A supplements for 6 weeks did not prevent them.
SupplementDEX Database · Child development
1 reference79.SupplementDEX Database: Child development — Effects of micronutrients on growth of children under 5 y of age: meta-analyses of single and multiple nutrient interventions2009
Meta-analyses of micronutrient trials in children under 5 found multimicronutrient interventions improved growth more than single-nutrient supplements, with iron alone showing smaller effects.
80.SupplementDEX Database: Chronic obstructive pulmonary disease (COPD) — Consumption of Vitamin K and Vitamin A Are Associated With Reduced Risk of Developing Emphysema: NHANES 2007-20162020
An NHANES analysis of 17,681 US adults found recommended vitamin A intake was associated with 33% lower emphysema odds (OR 0.67, 95% CI 0.44–1.00).
81.SupplementDEX Database: Cognitive performance — Effectiveness of intermittent iron and high-dose vitamin A supplementation on cognitive development of school children in southern Ethiopia: a randomized placebo-controlled trial2024
In 504 Ethiopian schoolchildren, intermittent iron plus high-dose vitamin A for 5 months improved some cognitive test scores versus placebo in this 2×2 factorial RCT.
SupplementDEX Database · Colorectal adenoma
1 reference82.SupplementDEX Database: Colorectal adenoma — Antioxidant supplement and long-term reduction of recurrent adenomas of the large bowel. A double-blind randomized trial2013
In 330 post-polypectomy patients over median 4 years, an antioxidant mix including 200 mcg selenium reduced adenoma recurrence risk by 39% versus placebo.
SupplementDEX Database · Colorectal cancer
1 reference83.SupplementDEX Database: Colorectal cancer — Antioxidant supplements for prevention of gastrointestinal cancers: a systematic review and meta-analysis2004
A meta-analysis of 14 gastrointestinal cancer prevention trials found antioxidant supplements including selenium did not reduce GI cancer incidence and beta-carotene increased mortality in high-quality trials.
SupplementDEX Database · Corneal abrasion
1 reference84.SupplementDEX Database: Corneal abrasion — The protective effect of vitamin A palmitate eye gel on the ocular surface during general anaesthesia surgery: a randomized controlled trial2024
An RCT of 60 surgical patients under general anesthesia found vitamin A palmitate eye gel protected the ocular surface and reduced corneal fluorescein staining versus taping alone.
86.SupplementDEX Database: Coronary artery bypass graft surgery — Therapeutic effects of olfactory training and systemic vitamin A in patients with COVID-19-related olfactory dysfunction: a double-blinded randomized controlled clinical trial2024
An RCT of 90 patients with COVID-19 smell loss found olfactory training improved recovery (76.9–86.7%) versus 26.7% in controls; adding oral vitamin A did not improve outcomes further.
87.SupplementDEX Database: Coronary artery bypass graft surgery — Evaluation and comparison of vitamin A supplementation with standard therapies in the treatment of patients with COVID-192022
An RCT of 182 COVID-19 outpatients found adding vitamin A 25,000 IU/day for 10 days to standard therapy significantly reduced fever, body aches, fatigue, and C-reactive protein versus standard treatment alone.
85.SupplementDEX Database: Coronary artery bypass graft surgery — Effect of vitamin A supplementation on clinical evolution in patients undergoing coronary artery bypass grafting, according to serum levels of zinc2012
An RCT in CABG patients found vitamin A supplementation raised retinol and β-carotene in zinc-replete patients and reduced hospitalization and ICU stay compared with controls.
SupplementDEX Database · Depression
1 reference88.SupplementDEX Database: Depression — Associations of Dietary Vitamin A and Beta-Carotene Intake With Depression. A Meta-Analysis of Observational Studies2022
A meta-analysis of 25 observational studies (100,955 participants) found higher dietary vitamin A (RR 0.83) and beta-carotene (RR 0.63) intake were inversely associated with depression.
SupplementDEX Database · Esophageal cancer
2 references89.SupplementDEX Database: Esophageal cancer — The association of dietary β-carotene and vitamin A intake on the risk of esophageal cancer: a meta-analysis2020
A meta-analysis of 14 studies found higher dietary β-carotene (OR 0.62) and vitamin A (OR 0.79) intake were associated with lower esophageal cancer risk.
90.SupplementDEX Database: Esophageal cancer — Meta-analysis of antioxidant intake and the risk of esophageal and gastric cardia adenocarcinoma2007
A meta-analysis of 10 studies found higher vitamin C (OR 0.49) and beta-carotene/vitamin A (OR 0.46) intake were inversely associated with esophageal adenocarcinoma risk.
SupplementDEX Database · Glaucoma
1 reference91.SupplementDEX Database: Glaucoma — Vitamin intake and glaucoma risk: A systematic review and meta-analysis2022
A meta-analysis of 8 studies (262,189 patients) found high vitamin A intake (OR 0.63) and vitamin B intake (OR 0.71) were associated with lower glaucoma prevalence.
92.SupplementDEX Database: Graft-versus-host disease — A randomized phase 2 trial of oral vitamin A for graft-versus-host disease in children and young adults2024
A phase 2 RCT of 80 HSCT recipients found pretransplant high-dose oral vitamin A reduced chronic GVHD at 1 year (5% vs 15%, P=0.02) and acute GI GVHD in as-treated analysis.
93.SupplementDEX Database: Human papillomavirus (HPV) — Topical and Systemic Retinoids for the Treatment of Genital Warts: A Systematic Review and Meta-Analysis2021
A systematic review of 6 studies (141 patients) found systemic retinoids achieved 56% complete response for genital warts versus no complete response with topical retinoids, with mucocutaneous side effects in 80% on systemic therapy.
SupplementDEX Database · Infant development
2 references94.SupplementDEX Database: Infant development — Vitamin A supplementation to prevent mortality and short- and long-term morbidity in very low birth weight infants2016
A meta-analysis of 120 studies found that there was a marginal reduction of the combined outcome of death or chronic lung disease (typical RR 0.92, 95% CI 0.84 to 1.01; typical RD -0.05, 95% CI -0.11 to 0.01; 4 studies, 1089 infants).
95.SupplementDEX Database: Infant development — Effects of early inhaled nitric oxide therapy and vitamin A supplementation on the risk for bronchopulmonary dysplasia in premature newborns with respiratory failure2014
A randomized trial of 793 infants found that combined therapy improved Bayley Scales of Infant Development II Mental and Psychomotor Developmental Index scores at 1 year compared with infants treated solely with iNO for the 500-749 g birth weight group.
SupplementDEX Database · Iron deficiency anemia
4 references96.SupplementDEX Database: Iron deficiency anemia — Clinical study of vitamin A combined with vitamin B in prevention and treatment of anemia in premature infants2019
A study in children/adolescents found that the ratio of blood transfusion in group C was lower than that in group A and B (P 0.05).
97.SupplementDEX Database: Iron deficiency anemia — Vitamin A and carotenoids during pregnancy and maternal, neonatal and infant health outcomes: a systematic review and meta-analysis2012
A meta-analysis found that among HIV-positive women, supplementation was protective against low birthweight (<2.5 kg) [risk ratio (RR) = 0.79 [95% confidence interval (CI) 0.64, 0.99]], but no significant effects on preterm delivery or small-for-gestational age were observed.
98.SupplementDEX Database: Iron deficiency anemia — Impact of vitamin A supplementation on anaemia and plasma erythropoietin concentrations in pregnant women: a controlled clinical trial2001
A randomized trial in women found that 30 mg there were no significant differences between vitamin A and control groups in the slope of the regression line between log10 erythropoietin and haemoglobin at enrollment or 38 wk, and between enrollment and follow-up within either group.
99.SupplementDEX Database: Iron deficiency anemia — The role of vitamins in the prevention and control of anaemia2000
A systematic review found that vitamin B6 effectively treats sideroblastic anaemia.
SupplementDEX Database · Leukemia
1 reference100.SupplementDEX Database: Leukemia — Effects of vitamin A on survival in patients with chronic myelogenous leukemia: a SWOG randomized trial1995
A randomized trial of 153 found that after adjustment for significant factors identified in an additional exploratory multivariate analysis, risk of clinical progression or death was 53% (P = 0.022) greater and risk of death 60% (P = 0.014) greater among busulfan patients.
SupplementDEX Database · Liver cancer
1 reference101.SupplementDEX Database: Liver cancer — A systematic review and meta-analysis of the association between vitamin A intake, serum vitamin A, and risk of liver cancer2018
A meta-analysis of 5 studies found that the meta-analysis of five studies showed no association between serum retinol and liver cancer (pooled risk ratio = 1.90 (0.40-9.02); n = 5 studies, I 2 = 92%).
SupplementDEX Database · Lung cancer
5 references102.SupplementDEX Database: Lung cancer — Association between Dietary and Supplemental Antioxidants Intake and Lung Cancer Risk: Evidence from a Cancer Screening Trial2023
In 98,451 PLCO participants, higher food-based antioxidant intake including lutein/zeaxanthin was associated with lower lung cancer risk (HR Q4 vs Q1 0.64); supplemental antioxidants showed no benefit.
103.SupplementDEX Database: Lung cancer — Changes in cytokine production in vitro during the early phase of birch-pollen immunotherapy2000
A study of 10 found that after a short decrease, probably owing to seasonal variation, the birch-pollen-specific proliferation and the interleukin (IL)-4, IL-5, and IL-10 production significantly increased when reaching the maintenance dose and during the subsequent pollen season.
104.SupplementDEX Database: Lung cancer — Vitamin A and cancer prevention II: comparison of the effects of retinol and beta-carotene1998
A randomized trial of 512 found that 30 mg/day the relative rate of mesothelioma (the most common single cause of death in our study) for those on retinol compared with those on beta-carotene was 0.24 (95% CI 0.07-0.86).
105.SupplementDEX Database: Lung cancer — Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease1996
A randomized trial of 18314 found that 25000 IU/day the active-treatment group had a relative risk of lung cancer of 1.28 (95 percent confidence interval, 1.04 to 1.57; P=0.02), as compared with the placebo group.
106.SupplementDEX Database: Lung cancer — Adjuvant treatment of stage I lung cancer with high-dose vitamin A1993
A randomized trial of 18 patients with stage i non-small-cell lung cancer found that 000 IU/day for 12 months daily oral administration of high-dose vitamin A is effective in reducing the number of new primary tumors related to tobacco consumption and may improve the disease-free interval in patients curatively resected for stage I lung cancer.
SupplementDEX Database · Malaria
2 references107.SupplementDEX Database: Malaria — Effect of vitamin A adjunct therapy for cerebral malaria in children admitted to Mulago hospital: a randomized controlled trial2012
A randomized trial of 142 children/adolescents found that vitamin A as adjunct therapy did not significantly reduce coma duration but there were fewer deaths in the vitamin A arm.
108.SupplementDEX Database: Malaria — Effect of vitamin A supplementation on morbidity due to Plasmodium falciparum in young children in Papua New Guinea: a randomised trial1999
A randomized trial of 241 children/adolescents found that the number of P. falciparum febrile episodes (temperature > or = 37.5 degrees C with a parasite count of at least 8000/microL) was 30% lower in the vitamin A group than in the placebo group (178 vs 249 episodes; relative risk 0.70 [95% CI 0.57-0.87], p=0.0013).
109.SupplementDEX Database: Non-Hodgkin lymphoma — Intake of antioxidant nutrients and risk of non-Hodgkin's Lymphoma in the Women's Health Initiative2012
An observational study of 1104 postmenopausal women found that cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI).
110.SupplementDEX Database: Nonmelanoma skin cancer — Association of Vitamin A Intake With Cutaneous Squamous Cell Carcinoma Risk in the United States2019
A study of 400 found that increased intake of dietary vitamin A is associated with decreased risk of incident SCC.
SupplementDEX Database · Osteoarthritis
1 reference111.SupplementDEX Database: Osteoarthritis — Failure of selenium-ace to improve osteoarthritis1990
In osteoarthritis patients over 6 months, Selenium-ACE did not outperform placebo on joint symptoms, though both groups showed nonsignificant improvement trends.
SupplementDEX Database · Ovarian cancer
2 references112.SupplementDEX Database: Ovarian cancer — Dietary vitamin A intake and the risk of ovarian cancer: a meta-analysis2020
A meta-analysis of 443179 participants found that a positive association between dietary vitamin A intake and ovarian cancer risk was found (RR = 0.816, 95%CI = 0.723-0.920, I2 = 48.4%, Pfor heterogeneity = 0.019).
113.SupplementDEX Database: Ovarian cancer — Risk of ovarian carcinoma and consumption of vitamins A, C, and E and specific carotenoids: a prospective analysis2001
An observational study of 80326 women found that the multivariate relative risks (95% confidence intervals [CIs]) for ovarian carcinoma among women in the highest versus lowest quintile of intake were 1.04 (95% CI, 0.72-1.51) for vitamin A from foods and supplements; 1.01 (95% CI, 0.69-1.47) for vitamin C; 0.88 (95% CI,.
SupplementDEX Database · Pancreatic cancer
1 reference114.SupplementDEX Database: Pancreatic cancer — The association between dietary vitamin A intake and pancreatic cancer risk: a meta-analysis of 11 studies2016
A meta-analysis of 2705 participants found that the RR (95% CI) of pancreatic cancer for highest category of vitamin A intake compared with lowest category was 0.839 (95% CI=0.712-0.988) with low heterogeneity detected (I 2 =17.8%, P heterogeneity =0.274).
SupplementDEX Database · Parkinson's disease
1 reference115.SupplementDEX Database: Parkinson's disease — Vitamin A and carotenoids and the risk of Parkinson's disease: a systematic review and meta-analysis2014
A meta-analysis of 13 epidemiologic studies found no significant overall association between lutein intake or blood levels and Parkinson's disease risk, though case-control data suggested a possible inverse lutein association.
116.SupplementDEX Database: Photorefractive keratectomy — A randomised, double masked, clinical trial of high dose vitamin A and vitamin E supplementation after photorefractive keratectomy2001
A randomized trial of 20 found that 25,000 IU/day retinol palmitate + 230 mg/day alpha tocopheryl nicotinate in the vitamin treated group, re-epithelialisation time was significantly faster (p = 0.029) and haze incidence was reduced (p = 0.035), especially for high myopic corrections (p = 0.043).
SupplementDEX Database · Prostate cancer
1 reference117.SupplementDEX Database: Prostate cancer — Diet, anthropometric measures and prostate cancer risk: a review of prospective cohort and intervention studies2004
A meta-analysis found that 2000 mg/day prospective studies are consistent with a protective role for selenium, and possibly vitamin E, pulses and tomatoes/lycopene, in the aetiology of prostate cancer.
118.SupplementDEX Database: Radiation proctopathy — A prospective, randomized, double-blind, placebo-controlled trial of retinol palmitate (vitamin A) for symptomatic chronic radiation proctopathy2005
A randomized trial in patients with chronic radiation proctopathy found that 10,000 IU/day for 90 days in our trial, retinol palmitate significantly reduced rectal symptoms of radiation proctopathy, perhaps because of wound-healing effects.
119.SupplementDEX Database: Retinopathy of prematurity — Oral vitamin A supplementation for ROP prevention in VLBW preterm infants2020
A study of 9 infants found that 3,000 IU/kg/day for 28 days the percentage of babies requiring treatment for ROP was 0 in treated and 16.6 in the un-treated group (p = 0.020).
120.SupplementDEX Database: Upper respiratory tract infection (URTI) — Oral vitamin A supplements to prevent acute upper respiratory tract infections in children up to seven years of age2024
A meta-analysis of 27351 participants found that we are uncertain of the effect of vitamin A supplementation on the number of acute URTIs over two weeks (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.92 to 1.09; I 2 = 44%; 3 studies, 22,668 participants; low-certainty evidence).
121.SupplementDEX Database: Urinary tract infections (UTIs) — Vitamin A supplementation is effective for improving the clinical symptoms of urinary tract infections and reducing renal scarring in girls with acute pyelonephritis: a randomized, double-blind placebo-controlled, clinical trial study2019
A randomized trial of 38 patients with utis and first episode of apn found that duration of fever (vitamin A group: 1.8 days, placebo: 3.1 days, p = 0.0026), urinary frequency (1.3 days vs. 2.8 days, p = 0.003) and poor feeding (2.3 days vs. 4.2 days, p = 0.005) were significantly lower in the vitamin A group.
SupplementDEX Database · Warts
1 reference122.SupplementDEX Database: Warts — Topical and systemic retinoids for the treatment of cutaneous viral warts: A systematic review and meta-analysis2021
A meta-analysis of 399 studies found that the complete response rate was 64% (95% CI, 46-78%; I 2 =80%) for topical treatment and 61% (95% CI, 44-76%; I 2 =69%) for systemic treatment.