vitamin · for dry skin
Vitamin A
Skin needs vitamin A to renew itself properly and to keep its oil glands working.
Say that in clinical terms
Vitamin A (retinol) is essential for skin cell differentiation, turnover, and sebaceous gland function. It promotes keratinocyte maturation, enhances the skin barrier, stimulates collagen production, and normalizes desquamation to prevent dry, flaky skin.
How strong is the research?
1 paper read, 1 supporting.
Who was studied: From prescription retinoid research and deficiency studies, not from ordinary supplements in well-fed people.
No RCT was found testing oral vitamin A (in any form) for dry skin or xerosis as a primary or secondary endpoint. The available oral vitamin A trials target skin aging (combination with topical retinoic acid, 2023 MDPI trial), cancer prevention (squamous cell carcinoma prevention, retinol 25,000 IU/day), sun-damaged skin cellular changes (DOI: 10.1158/1078-0432.ccr-03-0188), or acne. A 2022 systematic review and meta-analysis of RCTs on oral supplements for skin moisturising identified 66 trials but focused on collagen, ceramides, and hyaluronic acid — not vitamin A. Critically, at high doses (300,000–500,000 IU), retinol toxicity manifests as xerosis (dry skin) and cheilitis, suggesting the
How much to take
daily with a fat-containing meal
2500–5000 IU
Do not exceed 10,000 IU daily (preformed vitamin A). Pregnant women should not exceed 3,000 IU.
Before you take it
- NIH ODS Tolerable Upper Intake Level for preformed vitamin A (retinol) in adults aged 19+ is 3,000 mcg RAE/day (10,000 IU/day); this UL covers combined food and supplement intake and does not apply to provitamin A carotenoids such as beta-carotene.
- Preformed vitamin A is teratogenic at doses approaching or exceeding the UL; supplementation above 10,000 IU/day is contraindicated in pregnancy and in individuals who may become pregnant (can cause fetal malformations).
- Chronic intake above the UL causes hypervitaminosis A: manifestations include intracranial hypertension (pseudotumor cerebri), hepatotoxicity (elevated transaminases, hepatic fibrosis), bone resorption with increased fracture risk, and symptoms such as painful muscles/joints, fatigue, and depression.
- Concurrent use of retinoid medications (isotretinoin, acitretin, bexarotene, alitretinoin) with vitamin A supplements is contraindicated due to additive retinoid toxicity and elevated risk of hypervitaminosis A.
- Orlistat reduces absorption of fat-soluble vitamins including vitamin A; concurrent use may necessitate supplementation, but doses should be temporally separated.
- Underlying hepatic disease or chronic significant alcohol use lowers the threshold at which vitamin A supplementation causes liver toxicity.
- In populations not deficient in vitamin A, supplementation with preformed retinol has not demonstrated consistent benefit for vision, skin, or immune endpoints and introduces avoidable toxicity risk.
- Individuals using topical retinoids (tretinoin, adapalene, tazarotene) for skin concerns simultaneously taking oral vitamin A supplements accumulate additive retinoid exposure; this combination is particularly relevant to users treating dry or aging skin who may have active retinoid prescriptions
When to take it
Best taken: with food
What we make of it
An expert review of prescription retinoids for ageing skin, not a trial of supplements.
The detail
The source reads as a narrative review of retinoid therapy for skin ageing. Prescription retinoids are not the same thing as swallowing vitamin A.