Vitamin A: What It Does, Who Needs It, and What You Should Know

When you think of vitamin A, a fat-soluble nutrient critical for vision, immune function, and skin health. Also known as retinol, it’s not just a supplement—it’s a molecule your body uses to turn light into signals for your eyes and to keep your skin and mucous membranes functioning like barriers against infection. You get it from animal sources like liver, eggs, and dairy as retinol, or from plants like carrots and sweet potatoes as beta-carotene, which your body converts into active vitamin A as needed.

But here’s the catch: your body doesn’t flush out excess vitamin A like it does with vitamin C. That means taking too much—especially from supplements—can build up and cause serious problems. Liver damage, bone pain, dizziness, and even increased risk of fractures are real risks with long-term overuse. On the flip side, not getting enough can lead to night blindness, dry skin, and a weakened immune system. People with digestive disorders like Crohn’s or celiac disease, or those who’ve had gastric bypass surgery, are more likely to be deficient. And if you’re on a statin like atorvastatin, you need to be extra careful—high doses of vitamin A can strain your liver when combined with cholesterol meds.

It’s not just about popping a pill. Vitamin A works with other nutrients. Zinc helps your body use it. Iron status affects how well you convert beta-carotene. And if you’re pregnant, too much preformed vitamin A can harm the baby—so prenatal vitamins usually limit it to safe levels. That’s why most people get enough from food alone. A single medium carrot gives you more than enough for the day. You don’t need a 10,000 IU supplement unless a doctor confirms a deficiency.

Some of the posts below look at how vitamin A interacts with medications like atorvastatin, while others touch on related topics like skin health with calcipotriene (a vitamin D analog used for psoriasis) or nutrition during chemotherapy. You’ll find real-world advice on avoiding toxicity, understanding dietary sources, and recognizing when supplements actually help versus when they just add risk. No fluff. No guesswork. Just what you need to know to use vitamin A safely.