What vitamin A is
Vitamin A is a fat-soluble vitamin. That means it dissolves in fat, and your body stores it in the liver. Because it is stored, you do not need it every day, and you can also build up too much.
There are two forms in food. Preformed vitamin A, called retinol, comes from animal foods like liver, eggs, dairy, and fish. Provitamin A carotenoids, like beta-carotene, come from colorful plants such as carrots, sweet potatoes, spinach, and mango. Your body turns some of the beta-carotene into retinol as needed.
Adult men need about 900 micrograms of retinol activity equivalents a day. Adult women need 700. Most people in the United States get enough from food.
What vitamin A does
Vision is the classic job. Retinol is turned into a pigment in the retina that lets you see in dim light. The first sign of deficiency, worldwide, is night blindness.
Vitamin A also keeps the lining of your eyes, lungs, gut, and skin healthy. It supports the immune system, which is why children in poor countries who get vitamin A supplements have fewer severe infections. And it helps cells grow and specialize, which matters for growth in children and for skin turnover in adults.
Vitamin A and your skin: retinoids
Here is where vitamin A touches skincare. Retinoids are a family of drugs made from vitamin A. Tretinoin, sold as Retin-A, is the best-studied one. It is a prescription cream that speeds up skin cell turnover, unclogs pores, and over months builds new collagen. It is FDA-approved for acne and for fine wrinkles and sun damage.
Retinol, the weaker over-the-counter cousin, has to be converted in the skin before it works. It is gentler but slower. Adapalene and tazarotene are other retinoids. Isotretinoin, better known as Accutane, is an oral retinoid used for severe acne. Because it is a form of vitamin A, taking extra vitamin A pills while on isotretinoin can cause toxicity.
Zen IV Spa prescribes tretinoin for $99 and has an acne and rosacea program for $119, shipped to your home after a video visit.
Deficiency: who is at risk
Vitamin A deficiency is rare in the United States but common in parts of Africa and Southeast Asia. Here it mostly affects people with fat absorption problems, because vitamin A needs fat to be absorbed. That includes cystic fibrosis, celiac disease, Crohn's disease, and people who have had bariatric surgery. Chronic liver disease and heavy alcohol use also drain stores.
Signs include trouble seeing at night, dry eyes, dry rough skin, and frequent infections. A blood test for retinol can confirm it, though levels do not drop until liver stores are nearly gone.
Too much: the real risk for supplement users
Because vitamin A is stored, too much preformed vitamin A is harmful. The safe upper limit for adults is 3,000 micrograms, or 10,000 international units, a day from retinol. Some supplements and cod liver oil products come close to that. Taking several products at once is how people get into trouble.
Short-term overdose causes headache, nausea, dizziness, and blurred vision. Long-term excess causes bone pain, liver damage, hair loss, and dry cracked skin. In pregnancy, high doses of preformed vitamin A can cause birth defects, so pregnant women should stay well under the limit and avoid liver.
Beta-carotene from food does not cause this problem. Eating a lot of carrots can turn your palms a bit orange, but that is harmless. One caution: high-dose beta-carotene pills raised lung cancer risk in smokers in two large trials, so smokers should avoid them.
How Zen IV Spa can help
Zen IV Spa serves New York and New Jersey. If you want to know where you stand, a licensed nurse can draw vitamin and nutrient labs at your home, and our medical team reviews them on a free video visit. If your interest in vitamin A is really about your skin, our medical team can prescribe tretinoin, $99, or our acne and rosacea program, $119, after a video visit, shipped to your door. Learn more at /skin/ or call (332) 239-2005.
Common Questions
What foods are high in vitamin A?+
Liver, eggs, dairy, and oily fish for retinol. Carrots, sweet potatoes, spinach, kale, and mango for beta-carotene.
How much vitamin A do I need?+
About 900 micrograms a day for men and 700 for women. The safe upper limit from supplements is 3,000 micrograms.
Is retinol the same as vitamin A?+
Retinol is the active form of vitamin A. In skincare, retinol is a mild over-the-counter retinoid. Tretinoin is the stronger prescription version.
Can vitamin A help acne?+
Vitamin A pills are not a good acne treatment and can be toxic at high doses. Prescription retinoids like tretinoin, which are made from vitamin A, work very well.
Can you overdose on carrots?+
No. Beta-carotene from food does not build up to toxic levels. It can tint your skin slightly orange, which is harmless.
Should I take a vitamin A supplement?+
Most people do not need one. If you have a fat absorption problem or a confirmed low level, a clinician can recommend a dose.
Sources: NIH Office of Dietary Supplements, Vitamin A and Carotenoids Fact Sheet for Health Professionals, 2023; FDA prescribing information for tretinoin cream; Mayo Clinic, Vitamin A; the ATBC and CARET beta-carotene trials, NEJM, 1994 and 1996.
All treatments are medical services. Every guest is screened, and every treatment is prescribed by a licensed provider. Nothing on this page is medical advice for you personally, and the opinions summarized here belong to the doctors named, not to Zen IV Spa. Talk to a provider before starting or stopping anything.
