Does vitamin A help muscle growth?

Only a little, and only in children likely to be short of it. In a randomized trial of 3,377 rural Nepali children aged 1 to 5 at risk of deficiency, high-dose vitamin A every 4 months added 25 mm2 of arm muscle area over 16 months against controls, with no change in weight gain or height. We found no trial in healthy adults or in people doing strength training, and no systematic review of the question.

Unsettled. Whether extra vitamin A builds muscle in someone who already gets enough has never been tested. The trials are in children at risk of deficiency, children with sickle cell disease and surgical patients, and the adult data are surveys that cannot show cause.

Extra growth in upper arm muscle area, square millimeters

The first bar is the randomized comparison. The second compares treated children who had clinical deficiency and were already wasted with children who had no signs of deficiency, so it shows catch-up rather than a tested effect. Neither study reports an interval in the abstract, so none is drawn. Sources: cards ev-vamg-01 and ev-vamg-02 below.

What the trials found

The Nepali trial was randomized by ward, and its finding is narrow. Arm circumference grew 0.05 in (0.13 cm) more and arm muscle area 25 mm2 more in children given vitamin A. Weight and height did not respond. Children who started out wasted and showed clinical signs of deficiency gained more after treatment: 24 oz (672 g) of weight, about 0.39 in (1 cm) of height and 76 mm2 of muscle area against children without those signs. That second comparison was not randomized, and it describes recovery from deficiency.

In a randomized pilot of 22 children with sickle cell disease, given 3,000 or 6,000 IU of retinol a day for 8 weeks, muscle function improved mildly. There was no placebo group, and the abstract does not say by how much. In 36 patients having surgery on the aorta, an antioxidant mix that included beta-carotene did not protect handgrip or thigh strength, which fell after surgery to a similar extent on the mix and on placebo. The mix makes it impossible to say what beta-carotene alone did.

Adults, in observational data

Among 3,911 US adults aged 35 and over in the NHANES survey, higher total vitamin A intake was linked to more muscle mass in men, with an odds ratio of 1.019 (95% CI 1.010 to 1.027). In women the odds ratio of 1.006 (95% CI 0.998 to 1.013) did not reach significance. The survey does not report the difference in kilograms. In 68,002 UK Biobank participants aged about 64, higher retinol intake went with stronger handgrip in both sexes, among many nutrients tested at once, and the abstract gives no effect size. Both are associations. People who eat more vitamin A eat differently in other ways too.

Who should be careful

Not for everyone. Regular high doses of preformed vitamin A cause chronic toxicity, which the NIH describes as painful muscles and joints, dry skin, fatigue, depression and abnormal liver tests. Taking more in the hope of more muscle can produce the opposite of what you wanted.

Women who are or might be pregnant, and those who are breastfeeding, are advised by the NIH not to take more than 3,000 mcg RAE (10,000 IU) of vitamin A supplements a day. In the ATBC trial, 20 mg a day of beta-carotene for 5 to 8 years raised lung cancer risk and mortality in male smokers, so beta-carotene tablets are not a safe way around the limit for smokers.

What expert bodies say

We found no position from an expert body on vitamin A for muscle growth. The NIH Office of Dietary Supplements fact sheet has no passage on muscle building. It describes the toxicity, the pregnancy limit and the beta-carotene trial set out above.

How we searched

Searched: a local copy of PubMed on 7 October 2026, for vitamin A, retinol, retinoids, beta-carotene, carotenoids and retinoic acid with muscle mass, lean mass, sarcopenia, strength, grip and physical performance (209 hits, top 60 screened), and for carotenoids and retinol with frailty, walking speed and muscle mass (97 hits, top 30 screened). We also searched Europe PMC, ClinicalTrials.gov (10 records, none testing vitamin A on muscle), the NIH Office of Dietary Supplements and the web for reviews. None of the included studies has been retracted.

Included: three randomized trials, one non-randomized subgroup of one of them, two large surveys and three NIH passages.

Excluded: a tomato extract trial (lycopene is not a source of vitamin A), micronutrient mixes where vitamin A could not be separated, studies of combined antioxidant scores, trials of vitamins C and E with strength training, and cattle feeding studies.

What we read: abstracts, and the full text of the NHANES analysis, with each quotation checked against the source.

What we could not get: the full texts of all three randomized trials and the UK Biobank study, so the size of the muscle change in the sickle cell pilot and the grip effect remain unknown.

What would change this answer

A randomized trial of vitamin A at ordinary doses in adults, with or without strength training, measuring muscle mass or strength. We found none, run or registered.
A systematic review pooling the child trials that measured arm muscle.
Full reporting of the existing small trials, so the mild changes can be put in numbers.

How much vitamin A you need, and where it comes from in food, is in the vitamin A guide.

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

The same question for other foods (muscle growth)

Sources

ev-vamg-01 · Randomized controlled trial(s) · cluster randomized placebo-controlled trial, 60,000 microg RE every 4 months for 16 months · n = 3377
VA had no impact on annual weight gain or linear growth. However, arm circumference (AC) and muscle area (MA) growth improved in VA recipients, by 0.13 cm and 25 mm2, respectively, over controls.
Who: rural Nepalese nonxerophthalmic children aged 12-60 months
Effect: no impact on annual weight gain or linear growth; arm circumference +0.05 in (0.13 cm) and muscle area +25 mm2 vs control
Certainty: Children at risk of deficiency; says nothing about adults or training. Randomized by ward.
J Nutr, 1997 · checked 2026-10-07 · we read the abstract
ev-vamg-02 · Observational data · non-randomized comparison within a trial cohort · n = 34
Among initially wasted children (AC < 13.5 cm), VA-treated children (n = 34) gained additional weight (672 g), height (approximately 1 cm), muscle (76 mm2) and fat (79 mm2) areas, and subscapular skinfold (1.3 mm) compared to changes observed in nonxerophthalmic children.
Who: initially wasted xerophthalmic children treated with at least 120,000 RE, vs nonxerophthalmic children
Effect: additional weight 672 g, height about 0.39 in (1 cm), muscle area 76 mm2, fat area 79 mm2
Certainty: Treated deficient children vs non-deficient comparison group, not randomized. Shows catch-up when deficiency is corrected.
J Nutr, 1997 · checked 2026-10-07 · we read the abstract
ev-vamg-03 · Randomized controlled trial(s) · randomized double-blind dose-finding pilot trial, no placebo arm · n = 22
Mild improvements in erythrocyte indices, growth status, and muscle function occurred independent of hydroxyurea use.
Who: children with hemoglobin-SS sickle cell disease
Effect: mild improvements in erythrocyte indices, growth status and muscle function; serum vitamin A status unchanged
Certainty: Exploratory outcome, two doses compared, no placebo. Size of muscle change not given in the abstract (no_pmc).
J Pediatr Hematol Oncol, 2020 · checked 2026-10-07 · we read the abstract
ev-vamg-04 · Randomized controlled trial(s) · randomized double-blind placebo-controlled trial, beta-carotene plus vitamins C and E, zinc and selenium for 3-4 weeks · n = 18 per group
Handgrip and quadriceps strength decreased following surgery, but not to a significantly different extent in the placebo and supplemented groups.
Who: patients undergoing elective abdominal aortic aneurysmectomy
Effect: handgrip and quadriceps strength fell after surgery, not significantly different between groups
Certainty: Mixed supplement; cannot isolate beta-carotene.
Clin Nutr, 2002 · checked 2026-10-07 · we read the abstract
ev-vamg-05 · Observational data · cross-sectional study, weighted quantile sum mixture analysis · n = 3911
Table 4, Illustrated that, after adjusting for all covariates, there was a significant positive correlation between total vitamin A intake and muscle mass among American adult males, whereas there was no significant positive association in women (Male: OR: 1.019, 95% CI: 1.010–1.027, p < 0.001; Female: OR: 1.006, 95% CI: 0.998–1.013, p = 0.137).
Who: US adults aged 35 years and older in NHANES 2011-2016
Effect: men OR 1.019 (95% CI 1.010 to 1.027); women OR 1.006 (0.998 to 1.013)
Food Science & Nutrition, 2024, 12(12), Systematic Exploration of the Association Between Vitamin A Intakes and Sarcopenia Prevalence in American Adults · checked 2026-10-07 · we read the fulltext
ev-vamg-06 · Observational data · cross-sectional study · n = 68,002
The current data revealed negative associations between carbohydrate intake and handgrip strength as well as positive associations between oily fish, retinol and magnesium intake and grip strength in both sexes.
Who: UK Biobank participants aged about 64 years
Effect: positive association between retinol intake and grip strength in both sexes; effect size not in abstract
Certainty: Many nutrients tested at once; no effect size in abstract (no_pmc).
Mech Ageing Dev, 2020 · checked 2026-10-07 · we read the abstract
ev-vamg-07 · Position of an expert body · government fact sheet · n = —
Chronic hypervitaminosis A (regular consumption of high doses) can cause dry skin, painful muscles and joints, fatigue, depression, and abnormal liver test results [85].
Who: people taking high doses of preformed vitamin A
Effect: chronic hypervitaminosis A: dry skin, painful muscles and joints, fatigue, depression, abnormal liver tests
NIH Office of Dietary Supplements, Vitamin A and Carotenoids fact sheet for health professionals · checked 2026-10-07 · we read the section
ev-vamg-08 · Position of an expert body · government 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: pregnant and lactating women
Effect: no more than 3,000 mcg RAE (10,000 IU) preformed vitamin A a day from supplements
NIH Office of Dietary Supplements, Vitamin A and Carotenoids fact sheet for health professionals · checked 2026-10-07 · we read the section
ev-vamg-09 · Position of an expert body · government fact sheet · n = —
However, the ATBC trial found that supplementation with a large amount of beta-carotene (20 mg/day), with or without 50 mg/day vitamin E, for 5–8 years increased the risk of lung cancer and mortality (mainly from lung cancer and ischemic heart disease) in male smokers [70].
Who: male smokers in the ATBC trial
Effect: 20 mg/day beta-carotene for 5-8 years increased lung cancer and mortality
NIH Office of Dietary Supplements, Vitamin A and Carotenoids fact sheet for health professionals · checked 2026-10-07 · we read the section

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.