Does vitamin A improve eyesight?

Only if you are short of it. In children aged 6 months to 5 years in low- and middle-income countries, the 2022 Cochrane review found vitamin A supplements cut night blindness by 68% (RR 0.32, 95% CI 0.21 to 0.50, 2 studies, 22,972 children) on moderate-certainty evidence. In pregnant women, mostly where deficiency is common, night blindness fell by 21%. We found no trial or review showing that extra vitamin A sharpens sight in people who already get enough. The absolute rates behind those percentages are not in the abstracts we read.

Established. Lack of vitamin A damages the eye. NIH ODS describes night blindness as the first sign, from low levels of rhodopsin in the retina, and says the damage can spread to the cornea and end in permanent blindness. It calls vitamin A deficiency one of the top causes of preventable blindness in children. Correcting it in children at risk works, on moderate-certainty evidence.

Unsettled. Whether more vitamin A helps eyes that are not short of it has not been tested in a trial we could find. The closest evidence comes from an inherited eye disease, retinitis pigmentosa, and there the trials found no clear benefit.

What vitamin A and beta-carotene did against no supplement, relative risk

Pooled randomized trialsFollow-up of one trial

The first three rows come from populations at risk of deficiency in low- and middle-income countries. Below 1.0 means less of the problem, above 1.0 means more. The last row is an odds ratio from following a trial up after it ended. Sources: cards ev-vae-01, ev-vae-02, ev-vae-06 and ev-vae-13 below.

What the trials found

Children at risk of deficiency

The same Cochrane review found vitamin A cut Bitot's spots, an eye sign of deficiency, by 58% (RR 0.42, 95% CI 0.33 to 0.53, 5 studies, 1,063,278 children). That is also moderate-certainty evidence, from populations at risk of deficiency.

Pregnancy

The Cochrane review of vitamin A in pregnancy found it lowered maternal night blindness, RR 0.79 (95% CI 0.64 to 0.98). That result rests on two trials, and the benefit is limited to populations where deficiency is common.

Retinitis pigmentosa

This is the one place where vitamin A has been tried as a treatment for eyes that are failing for another reason. A 2020 Cochrane review of 4 trials in 944 people aged 4 to 55 found no study reporting any benefit of vitamin supplements on loss of visual acuity. In the vitamin A trial, the yearly loss on a standard letter chart was 1.1 and 0.9 letters in the two groups, on very low-certainty evidence. One electrical test of the retina declined a little more slowly on vitamin A, 6.1% against 7.1% a year. The authors conclude it is uncertain whether vitamin A, DHA or both help.

A 2023 reanalysis went back to the trial from 1984 to 1992 that made vitamin A a standard treatment for this disease, and added genetic data from 765 patients. The effect of vitamin A on progression across the whole group was not detectable. That was an analysis done long after the trial, so it is not the final word, and it does not support the old advice either.

Deficiency in rich countries

A 2026 systematic review collected 61 children in high-income countries with eye damage from vitamin A deficiency, from 43 case reports and series. Of those, 21.3% had night blindness only, 29.5% had dry patches or Bitot's spots on the white of the eye and 29.5% had dryness, ulcers or scarring of the cornea. A collection of cases cannot say how common this is. It does show that deficiency still harms eyes in places where most people never meet it.

Macular degeneration

In the AREDS2 trial of older adults with age-related macular degeneration, NIH ODS reports that the formula with lutein and zeaxanthin cut progression to late disease by a further 20% over 10 years compared with the formula containing beta-carotene. That is a summary from an agency, with no absolute numbers given. In this disease, the formula without the vitamin A precursor did better.

Who should be careful

Not for everyone. Too much preformed vitamin A can harm the eyes it is bought for. NIH ODS lists severe headache, blurred vision, nausea and dizziness as signs of acute toxicity, typically at doses more than 100 times the recommended amount. It advises women who are or might be pregnant, and those breastfeeding, not to take more than 3,000 mcg RAE (10,000 IU) a day of vitamin A supplements.

In young children, single high doses of vitamin A doubled the risk of vomiting in the next 48 hours, RR 1.97 (95% CI 1.44 to 2.69, 4 studies, 10,541 children), on moderate-certainty evidence. The effect was short-lived. The absolute rates are not in the abstract.

Beta-carotene supplements carry their own risk. In 10-year follow-up of the AREDS2 trial in 3882 older adults, those randomly assigned to beta-carotene had higher odds of lung cancer, OR 1.82 (95% CI 1.06 to 3.12). The odds with lutein and zeaxanthin, 1.15 (95% CI 0.79 to 1.66), did not differ significantly. Beta-carotene was a secondary part of that trial's design.

What expert bodies say

NIH ODS treats night blindness as the first sign of vitamin A deficiency and says deficiency is rare in the United States. It reports that the Food and Nutrition Board advises against beta-carotene supplements for the general population, except as a source of vitamin A to prevent deficiency. Those are agency positions without analyses of their own. We did not find a body that recommends vitamin A supplements to improve eyesight in people who are not deficient.

If your night vision has got worse, the cause is worth finding out before buying a supplement. The trials above show vitamin A helping eyes only where deficiency was the problem.

How we searched

Searched: a local copy of PubMed, queried on 7 October 2026 across all study types. A broad query for vitamin A, retinol or beta-carotene with night blindness, dry eye from deficiency, vision, visual acuity, retinitis pigmentosa or dark adaptation returned 891 hits. A query for trials in retinitis pigmentosa returned 18, and a query for trials on night blindness or dark adaptation returned 62, with no trial in well-nourished adults. We also searched the NIH Office of Dietary Supplements fact sheet, a trial registry and the web for trials and reviews from 2024 and 2025.

Included: three Cochrane reviews, a genetic reanalysis of the founding trial in retinitis pigmentosa, the 10-year follow-up of AREDS2, a systematic review of case reports from high-income countries and five sections of the NIH fact sheet.

Excluded: a Cochrane review of vitamin A in measles, whose trials reported no eye outcomes. Earlier versions of the children's review and a withdrawn version of the pregnancy review. Reviews of antioxidant mixtures for macular degeneration, where vitamin A cannot be separated from the rest. The 1993 trial in retinitis pigmentosa, which has no abstract in our copy of PubMed, so its reanalysis is cited instead. A review on healthy adults found on the web, from a journal outside our list of trusted sources and mixing in lutein and zeaxanthin.

What we read: abstracts, from the PubMed files, and the NIH fact sheet. All sources with a PubMed record were checked against Retraction Watch, with no retractions.

What we could not get: the full texts of the Cochrane reviews, with doses per trial and any data on dark adaptation. Also the results of two registered US National Eye Institute trials of vitamin A palmitate in macular degeneration with slow dark adaptation, NCT03478878 and NCT03478865, which we could not find published.

What would change this answer

Published results of the two National Eye Institute trials above. They would show whether high-dose vitamin A helps eyes that adapt slowly to the dark in early macular degeneration.
A randomized trial of vitamin A on night vision in well-nourished adults whose vitamin A status is borderline. We found none.
The full texts of the Cochrane reviews, which would give the doses used and the absolute rates behind the percentages on this page.

The rest of the nutrient, in one place. Vitamin A: the supplement that increased cancer in a randomized trial → What it does, how much you need, who runs short, and what too much does, with the evidence level shown on every line.

The full guide

Vitamin A: the supplement that increased cancer in a randomized trial

Sources

ev-vae-01 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 22,972 children (night blindness, 2 studies); 1,063,278 (Bitot's spots, 5 studies)
VAS reduced the incidence of diarrhoea (RR 0.85, 95% CI 0.82 to 0.87; 15 studies, 77,946 children; low-certainty evidence), measles (RR 0.45, 95% CI 0.30 to 0.69; 2 studies, 1,982 children; low-certainty evidence), Bitot's spots (RR 0.42, 95% CI 0.33 to 0.53; 5 studies, 1,063,278 children; moderate-certainty evidence), night blindness (RR 0.32, 95% CI 0.21 to 0.50; 2 studies, 22,972 children; moderate-certainty evidence), and VAD (RR 0.71, 95% CI 0.65 to 0.78; 4 studies, 2262 children, moderate-certainty evidence).
Who: children aged six months to five years in low- and middle-income countries, randomized trials of vitamin A supplementation
Effect: night blindness RR 0.32 (95% CI 0.21 to 0.50); Bitot's spots RR 0.42 (0.33 to 0.53); moderate certainty
Certainty: moderate-certainty evidence (GRADE); populations at risk of deficiency
Cochrane Database Syst Rev, 2022 · checked 2026-10-07 · we read the abstract
ev-vae-02 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = over 310,000 women (night blindness: two trials)
Vitamin A supplementation reduces the risk of maternal night blindness (RR 0.79, 95% CI 0.64 to 0.98; two trials).
Who: pregnant women in randomized trials of vitamin A supplementation, mostly in areas with endemic vitamin A deficiency
Effect: maternal night blindness RR 0.79 (95% CI 0.64 to 0.98)
Certainty: two trials for this outcome; benefit limited to deficient populations
Cochrane Database Syst Rev, 2015 · checked 2026-10-07 · we read the abstract
ev-vae-03 · Meta-analysis or systematic review · Cochrane systematic review of RCTs, no meta-analysis · n = 944
The rest of the trials reported no adverse events, and no study reported any evidence of benefit of vitamin supplementation on the progression of visual acuity loss.
Who: people aged 4 to 55 years with retinitis pigmentosa in randomized trials of vitamin A, DHA or both
Effect: no evidence of benefit on visual acuity; ETDRS decline 1.1 vs 0.9 letters per year in the vitamin A trial; very low certainty
Certainty: very low certainty; one small ERG difference favored vitamin A (6.1% vs 7.1% decline per year)
Cochrane Database Syst Rev, 2020 · checked 2026-10-07 · we read the abstract
ev-vae-04 · Meta-analysis or systematic review · Cochrane systematic review of RCTs · n = 944
Based on the results of four studies, it is uncertain if there is a benefit of treatment with vitamin A or DHA, or both for people with RP.
Who: people with retinitis pigmentosa in randomized trials
Effect: uncertain benefit; no pooled estimate
Certainty: authors' conclusion
Cochrane Database Syst Rev, 2020 · checked 2026-10-07 · we read the abstract
ev-vae-05 · Randomized controlled trial(s) · secondary genetic analysis of randomized controlled trials · n = 765 sequenced samples
Surprisingly, the effect of vitamin A progression in the cohort as a whole was not detectable, with or without data from subsequent trials.
Who: patients with retinitis pigmentosa from the 1984 to 1992 randomized trial of vitamin A and E, with sequenced DNA
Effect: vitamin A effect on progression not detectable; vitamin E deleterious
Certainty: post hoc reanalysis; subgroup effects discussed
JCI Insight, 2023 · checked 2026-10-07 · we read the abstract
ev-vae-06 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 10,541
There was an increased risk of vomiting within the first 48 hours of VAS (RR 1.97, 95% CI 1.44 to 2.69; 4 studies, 10,541 children; moderate-certainty evidence).
Who: children aged six months to five years given high-dose vitamin A capsules in randomized trials
Effect: vomiting within 48 hours RR 1.97 (95% CI 1.44 to 2.69), moderate certainty
Certainty: moderate certainty; transient effect of single large doses
Cochrane Database Syst Rev, 2022 · checked 2026-10-07 · we read the abstract
ev-vae-07 · Laboratory or animal data · systematic review of case reports and case series · n = 61 cases
Xerophthalmia was graded according to the most advanced finding for each case: 21.3% had night blindness only; 29.5% had conjunctival xerosis or Bitot spots; 29.5% had corneal xerosis, ulceration or scarring; 1.6% had xerophthalmia fundus only; and 18.0% had ocular manifestations associated with VAD that are not encompassed under the WHO classification.
Who: children under 18 in high-income countries with ocular features of vitamin A deficiency, 43 case reports and series
Effect: night blindness only 21.3%; conjunctival xerosis or Bitot spots 29.5%; corneal xerosis, ulceration or scarring 29.5%; restrictive diets 75%, autism 49%
Certainty: case series, no denominator; level D pending decision on case series
Surv Ophthalmol, 2026 · checked 2026-10-07 · we read the abstract
ev-vae-08 · Position of an expert body · agency fact sheet · n = —
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 [1,27,28]. Xerophthalmia also affects the cornea and can eventually lead to permanent blindness; vitamin A deficiency is one of the top causes of preventable blindness in children [28].
Who: people with vitamin A deficiency, mainly in low-income countries
Effect: no effect size; deficiency is a top cause of preventable childhood blindness
Certainty: agency position without own analysis
NIH Office of Dietary Supplements, Vitamin A and Carotenoids Fact Sheet for Health Professionals · checked 2026-10-07 · we read the section
ev-vae-09 · Position of an expert body · agency fact sheet · n = —
Experts advise women who are or might be pregnant and those who are lactating not to take high doses (more than 3,000 mcg RAE [10,000 IU] daily) of vitamin A supplements [1].
Who: adults; women who are or might be pregnant and lactating women
Effect: acute toxicity above about 100 times the RDA; pregnancy cap 3,000 mcg RAE (10,000 IU) daily
Certainty: agency position without own analysis
NIH Office of Dietary Supplements, Vitamin A and Carotenoids Fact Sheet for Health Professionals · checked 2026-10-07 · we read the section
ev-vae-10 · Position of an expert body · agency fact sheet · n = —
Resulting signs and symptoms typically include severe headache, blurred vision, nausea, dizziness, aching muscles, and coordination problems.
Who: people taking one or a few very high doses of preformed vitamin A
Effect: no effect size; doses typically more than 100 times the RDA
Certainty: agency position without own analysis
NIH Office of Dietary Supplements, Vitamin A and Carotenoids Fact Sheet for Health Professionals · checked 2026-10-07 · we read the section
ev-vae-11 · Position of an expert body · agency fact sheet · n = —
However, the FNB advises against the use of beta-carotene supplements for the general population, except as a provitamin A source to prevent vitamin A deficiency.
Who: general population; smokers at particular risk in ATBC and CARET trials
Effect: no UL for beta-carotene; supplements not advised
Certainty: agency position without own analysis
NIH Office of Dietary Supplements, Vitamin A and Carotenoids Fact Sheet for Health Professionals · checked 2026-10-07 · we read the section
ev-vae-12 · Position of an expert body · agency fact sheet summarizing a randomized trial · n = 3,882 followed up
After 10 years, participants who had taken the AREDS2 supplement with lutein and zeaxanthin had an additional 20% reduced risk of progression to late AMD compared with those who took the supplement containing beta-carotene.
Who: older adults with age-related macular degeneration in the AREDS2 trial and follow-up
Effect: additional 20% reduced risk of progression to late AMD with lutein and zeaxanthin vs beta-carotene formula
Certainty: agency summary; primary AREDS2 paper not carded here
NIH Office of Dietary Supplements, Vitamin A and Carotenoids Fact Sheet for Health Professionals · checked 2026-10-07 · we read the section
ev-vae-13 · Randomized controlled trial(s) · epidemiologic follow-up of a randomized controlled trial · n = 3882
At 10 years, the odds ratio (OR) of having lung cancer was 1.82 (95% CI, 1.06-3.12; P = .02) for those randomly assigned to beta carotene and 1.15 (95% CI, 0.79-1.66; P = .46) for lutein/zeaxanthin.
Who: older adults with intermediate age-related macular degeneration in the AREDS2 trial, followed 5 years after the trial
Effect: lung cancer OR 1.82 (95% CI 1.06 to 3.12) with beta-carotene; OR 1.15 (0.79 to 1.66) with lutein/zeaxanthin; late AMD HR 0.91 (0.84 to 0.99) lutein/zeaxanthin vs none
Certainty: self-reported lung cancer validated with records; beta-carotene was a secondary randomization
JAMA Ophthalmol, 2022 · checked 2026-10-07 · we read the abstract

How this page was made. Evidence was extracted from primary sources into cards, every number was re-checked against the source, and the text was written from those cards. Bioma Learn has no human medical reviewer at this time, and we say so rather than invent one. Methodology. This is information, not medical advice.