Vitamin A and acne: doses, safety and pregnancy

Vitamin A has a real history in acne treatment. Before isotretinoin was approved by the FDA in 1982, doctors used high doses of vitamin A for severe acne, and isotretinoin itself is closely related to vitamin A in its chemistry. The problem is the dose. The amounts that cleared acne in those trials were many times the safe upper limit, and preformed vitamin A at high doses can cause birth defects. This guide explains what the research shows, how to read a supplement label, and which forms of vitamin A have the best evidence. It is part of Skinli's acne diet guide.

Skinli gives general education and is not a doctor or dietitian. Ask a doctor or pharmacist before you take any vitamin A supplement, and do not take one if you are pregnant or could become pregnant without talking to your doctor first.

Two kinds of vitamin A

The NIH Office of Dietary Supplements (ODS) describes two forms:

• Preformed vitamin A (retinol and retinyl esters such as retinyl palmitate), found in liver, fish, eggs and dairy, and in many supplements. This is the form with an upper limit and a risk of birth defects.
• Provitamin A carotenoids, mainly beta-carotene, found in colored fruits and vegetables. The body turns some of it into vitamin A. The ODS says beta-carotene is not known to cause birth defects. Too much of it over a long time can turn the skin yellow-orange, which reverses when you stop.

A 2024 review of acne supplements in the Journal of Clinical and Aesthetic Dermatology found vitamin A in the form of beta-carotene, at 450 micrograms, and retinyl palmitate, at 900 to 6,100 micrograms, in the products it examined.

Why vitamin A might help acne

The 2024 supplement review says some forms of vitamin A shrink oil glands and slow the buildup of skin cells that blocks pores. Both are steps in how acne forms. Isotretinoin works in a related way. Its FDA label describes it as 13-cis-retinoic acid, related to both retinoic acid and retinol, the main form of vitamin A. That link is why doctors looked at plain vitamin A for acne before isotretinoin existed. Among supplements sold for acne, zinc has more trial evidence, covered in zinc for acne.

What the trials found

The vitamin A trials for acne are old and small. Two 2022 reviews found 9 studies, 8 clinical trials and one case report, and acne improved in 8 of them. Doses ranged from 36,000 to 500,000 IU a day, and 100,000 IU was the most common. Improvement took 7 weeks to 4 months. The reviews say the studies had limited controls, and many were published more than 50 years ago without the standards of modern trials.

The trials do not agree on the dose that works:

• A 1981 study in the International Journal of Dermatology found vitamin A ineffective at 50,000 to 100,000 IU a day. It worked only at 300,000 IU for women and 400,000 to 500,000 IU for men.
• The 2024 supplement review describes 4 trials in which 100,000 IU a day cleared acne.

Both doses are 10 to 50 times the adult upper limit of 10,000 IU. The 1981 authors wrote that the danger of vitamin A poisoning at their doses had been exaggerated. Today's NIH limits are far lower, and the 2022 reviews stress close monitoring by a doctor.

The 2022 reviews looked at vitamin A as a possible stand-in for isotretinoin when patients could not get it. Their conclusion was cautious. Side effects resembled those of isotretinoin, mostly dry lips, dry skin and headaches. Vitamin A causes birth defects, and the reviews say avoiding pregnancy for at least three months after stopping is critical. Because vitamin A is sold without a prescription, they say strict monitoring by a doctor cannot be guaranteed.

Safety limits from the NIH

The ODS sets these upper limits for preformed vitamin A from food and supplements together:

Age	Upper limit per day
9 to 13	1,700 micrograms
14 to 18, including pregnancy	2,800 micrograms
19 and over, including pregnancy	3,000 micrograms (10,000 IU)

The limits apply to preformed vitamin A only. If a supplement gets part of its vitamin A from beta-carotene, only the preformed part counts toward the limit.

The ODS describes two kinds of harm:

• Too much over time: dry skin, painful muscles and joints, tiredness, depression and abnormal liver tests.
• A single large dose: severe headache, blurred vision, nausea, dizziness, aching muscles and poor coordination.

Because the body stores vitamin A in the liver, levels can build up.

Vitamin A in food

Most people get enough vitamin A from food. The ODS says vitamin A deficiency is uncommon in the United States, and that average intakes from food in 2017 to 2018 were 682 micrograms a day for men and 616 micrograms for women, well below the upper limit. Liver is the exception: a 3 ounce serving of fried beef liver provides 6,582 micrograms, more than twice the adult upper limit in one meal. Sweet potatoes, spinach and carrots are rich in beta-carotene instead.

Beta-carotene supplements

Beta-carotene may seem the safer choice, and in pregnancy it is: the ODS says it is not known to cause birth defects. It still carries a warning. In two large trials, high-dose beta-carotene, taken alone in one and with vitamin A in the other, raised the risk of lung cancer in smokers. The second trial also included men exposed to asbestos at work. The ODS says the expert board that sets nutrient limits advises against beta-carotene supplements for the general population, except to prevent vitamin A deficiency. No trial has tested beta-carotene for acne.

Pregnancy

The ODS says total intakes of preformed vitamin A above the upper limit can cause birth defects of the eye, skull, lungs and heart. It advises women who are or might be pregnant, and those who are breastfeeding, not to take more than 3,000 micrograms (10,000 IU) a day of vitamin A supplements.

A 2021 study in Dermatology Practical and Conceptual checked 49 acne supplements sold online. It found:

• 26 contained vitamin A.
• 6 contained more than 10,000 IU.
• 3 were likely to cause birth defects at the listed dose.
• 2 of the 6 high-dose products had no pregnancy warning, including the one with the highest dose.

The authors add that labels report vitamin A in either IU or micrograms, and that the labeling rules may confuse buyers about the dose. If you could become pregnant, check every product for preformed vitamin A, and read pregnancy acne for treatments considered safe.

Reading a supplement label

Look for three things on any product that contains vitamin A:

• The form. Retinol, retinyl palmitate and retinyl acetate are preformed vitamin A. Beta-carotene is the plant form.
• The amount of each form. The ODS gives an example: a label listing 3,000 micrograms of vitamin A, 60 percent from beta-carotene, provides 1,200 micrograms of preformed vitamin A.
• Other products you take. Multivitamins add to the total, and the ODS says cod liver oil supplements also provide vitamin A.

Vitamin A and acne medicines

The FDA-approved label for isotretinoin capsules says to avoid taking them with supplements that contain vitamin A. Isotretinoin is closely related to vitamin A, and together they may increase isotretinoin's side effects. The ODS adds that retinoid medicines taken by mouth raise the risk of vitamin A toxicity when combined with vitamin A supplements. Multivitamins count, so tell your prescriber about every supplement you take. The Accutane side effects guide covers the rest of that medicine's safety rules.

Vitamin A that goes on the skin

The form of vitamin A with strong evidence for acne goes on the skin. Retinoids are creams and gels related to vitamin A, such as adapalene and tretinoin. The 2024 acne guideline from the American Academy of Dermatology (AAD) recommends topical retinoids based on moderate certainty evidence from 20 studies. Retinoids for acne explains how to start one.

The NHS says a pharmacist can recommend acne supplements such as vitamin A. Given the dose problems above, a retinoid cream is the vitamin A option to ask about first.

A practical approach

1. Use vitamin A on the skin first. Adapalene 0.1 percent is one of the two treatment gels in Skinli's plan, and analyze your skin builds a routine around it.
2. If you take a supplement, check the label. Find the preformed vitamin A (retinol or retinyl palmitate) and keep your total, including multivitamins, below the upper limit for your age.
3. Do not self-treat at trial doses. The doses that cleared acne in trials need a doctor's supervision.
4. Stop and see a doctor if you get headaches, blurred vision, dizziness, or muscle or joint pain while taking a supplement.