Vitamin B2 (Riboflavin): What It Does and How to Use It

Vitamin B2, also called riboflavin, helps your body turn food into energy and keeps your skin, eyes, and nerves healthy. If you eat a balanced diet you probably get enough, but certain people can benefit from extra riboflavin. This page explains where to find B2, signs of low levels, safe doses, and simple tips for taking it.

Food Sources and Daily Needs

Good food sources include milk, yogurt, eggs, lean meat, green vegetables, nuts, and fortified cereals. A typical adult needs about 1.1–1.3 mg per day, though pregnant and breastfeeding women may need a bit more. Vegans and people who avoid dairy should check their intake because plant sources may provide less riboflavin.

Who Might Need a Supplement

People with certain health conditions—like chronic diarrhea, celiac disease, or alcohol dependence—can have trouble absorbing B2. Older adults and people on strict diets may also fall short. Some migraine sufferers find riboflavin helpful; clinical trials often use 400 mg per day for prevention, which is far above the daily nutritional need and should be taken under a doctor’s guidance.

Riboflavin supplements come alone or in B-complex vitamins. If you take a multi B vitamin, read the label to see how much riboflavin it contains. B2 is water soluble, so your body excretes excess in urine. That can turn urine bright yellow—harmless, but it can alarm you if you aren't warned.

Side effects are rare at normal doses. Very high doses can cause stomach upset or diarrhea. People with sensitivity to yellow dyes should note that riboflavin itself colors urine yellow, which is not a dye issue. If you take prescription drugs, check with your doctor. Some medicines, like certain antibiotics and chemotherapy drugs, can affect B2 levels or interact with supplements.

Tips for taking riboflavin: take it with food to reduce stomach upset, keep a consistent routine each day, and store supplements away from light since riboflavin breaks down when exposed to sunlight. If you want to boost dietary B2, try a breakfast of fortified cereal with milk and a boiled egg—simple, cheap, and effective.

Testing for deficiency is usually done with blood or urine tests. Common deficiency signs include sore throat, cracks at the corners of the mouth, swollen tongue, and dry skin. These signs often appear with other B vitamin deficiencies, so lab testing helps clarify the cause.

If you think you are deficient, start by improving your diet. Use supplements if a clinician recommends them. For migraine prevention, talk to a neurologist before starting high-dose riboflavin. Keep track of other vitamins and medications you take to avoid surprises. Riboflavin is a small nutrient with a clear role—get the right amount and your body will thank you.

Pregnant or breastfeeding? Talk to your doctor before taking supplements. Dosage needs change and a clinician can help avoid excess or interactions. Keep all supplements listed with your healthcare team so everyone knows what you take. It's quick and worth it today.