Skip to main content
URMC / Encyclopedia / Content


Other name(s):

vitamin B-2, lactoflavin

General description

Riboflavin (also known as vitamin B-2) is a member of the B family of vitamins (B complex). It’s a water-soluble vitamin. Excess amounts are excreted through your kidneys. It makes the urine bright yellow. Riboflavin is an important antioxidant. Like the other B vitamins, it helps make energy.

Riboflavin is one of a series of enzymes called flavoproteins. There are over 40 known flavoproteins. They each play a role in the oxidation processes in the body. This helps create energy.

Medically valid uses

Riboflavin is used to treat deficiencies in the diet and nutrient issues. It’s used to treat rare genetic problems that keep flavoproteins from forming. It’s used to treat hormonal disorders. It’s used with exposure to sunlight (phototherapy) to treat jaundice in newborns.

Unsubstantiated claims

There may be benefits that have not yet been proven through research. 

Riboflavin may improve the health of your skin. It may boost energy.

Riboflavin is claimed to prevent migraine headaches. It cannot treat a migraine once it starts.

Recommended intake

The amount of riboflavin you need depends on your age. After the age of 14, men and women need different amounts. Most people in the U.S. get enough riboflavin from milk, milk products, bread, meat, and cereals. Grains and cereals have added riboflavin in the U.S.

Riboflavin is measured in milligrams (mg). Riboflavin comes as 25 mg, 50 mg, and 100 mg tablets. It’s also available in combinations (B complex). Whether from food or supplements, your body can’t absorb more than 27 mg at a time.

Bacteria in the large intestine produce riboflavin that the body can use if it doesn't get enough from food.

The RDA is the recommended dietary allowance.



Infants (0 to 6 months)

0.3 mg*

Infants (7 months to 1 year)

0.4 mg*

Children (1 to 3 years)

0.5 mg

Children (4 to 8 years)

0.6 mg

Children (9 to 13 years)

0.9 mg

Males (14 to 18 years)

1.3 mg

Males (19 years and older)

1.3 mg

Females (14 to 18 years)

1.0 mg

Females (19 years and older)

1.1 mg

Pregnant women

1.4 mg

Breastfeeding women

1.6 mg

*Adequate intake. This is based on the average intake in healthy, breastfed infants.

Food source

Nutrient content per 100 grams

Dried yeast

4.28 mg

Beef liver

2.9 mg

Chicken liver

2.5 mg


0.92 mg

Parmesan cheese

0.73 mg


0.55 mg

Cheddar cheese

0.46 mg


0.44 mg


0.35 mg


0.34 mg

Riboflavin is stable in heat when it’s dry. This means it doesn’t need to be refrigerated. But it breaks down more easily when moist and heated. Riboflavin is sensitive to light. Store foods that have riboflavin in light-resistant containers. For instance, up to 85% of the riboflavin in milk may be destroyed if exposed to sunlight.

Because riboflavin dissolves in water, a lot of it can be lost when foods are boiled. Less is lost by steaming or microwaving. Vegetables can lose about 30% to 40% of their riboflavin during cooking.

Some people need more riboflavin from supplements. These include people who don’t consume enough milk or other animal products.

Athletes need more riboflavin. Athletes who are vegetarian and don't include milk or eggs in their diets are at risk of getting too little riboflavin.

You may need more if you have irritable bowel syndrome or liver disease, or if you drink a lot of alcohol.

Women who are pregnant or breastfeeding may need to take vitamin supplements. But you should talk to your healthcare provider before doing so.

Riboflavin deficiency rarely occurs by itself. It’s more common with other B-vitamin and protein deficiencies. Symptoms of deficiency include:

  • Swelling of your tongue, throat, or lining of your mouth

  • Cracking on your lips

  • Tears at the corners of your mouth

  • Itchy skin

  • Joint swelling

  • Seborrheic dermatitis, a condition that causes red patches of skin, often on your scalp

  • Hair loss

  • Reproductive problems

  • Eye problems, such as burning, itching, blurred vision, light sensitivity, and blood vessels growing on the clear part of your iris. Cataracts may develop if deficiency is severe and prolonged.

Riboflavin deficiency may affect your bone marrow. It may lower your red blood cell count. This can lead to anemia.

Side effects, toxicity, and interactions

There are no known side effects of too much riboflavin. Excess riboflavin comes out in your urine.

There are no known food or medicine interactions with riboflavin.

Medical Reviewers:

  • Brittany Poulson MDA RDN CD CDE
  • Heather M Trevino BSN RNC
  • Rita Sather RN