Riboflavin is a water-soluble vitamin that the body needs to remain healthy. Humans cannot make riboflavin, so they must get it from foods in their diet. Riboflavin is also called vitamin B2.


Riboflavin has a broad range of activities related to the conversion of nutrients into energy, making other vitamins and minerals available to the body, and acting as an antioxidant to remove free radicals from cells.



Recommended dietary allowance (mg/day)

Children 0-6 mos.

0.3 (AI)

Children 7-12 mos.


Children 1-3 yrs.


Children 4-8 yrs.


Children 9-13 yrs.


Boys 14-18 yrs.


Girls 14-18 yrs.


Men 19≥ yrs.


Women 19≥ yrs.


Pregnant women


Breastfeeding women



Riboflavin (mg)

Yogurt, low fat, 1 cup


Milk, 2%, 1 cup


Tempeh, cooked, 4 oz.


Beef tenderloin, broiled, 4 oz.


Milk, nonfat, 1 cup


Egg, boiled, 1 large


Almonds, roasted, 1 oz.


Spinach, cooked, ½ cup


Chicken, dark meat, roasted, 3 oz.


Salmon, broiled, 3 oz.


Asparagus, cooked, ½ cup


Chicken, light meat, roasted, 3 oz.


Broccoli, steamed, ½ cup


Bread, white, enriched, 1 slice


Bread, whole wheat, 1 slice


AI = Adequate intake

mg = milligram

SOURCE: Office of Dietary Supplements. National Institutes of Health. “Riboflavin: Fact Sheet for Health Professionals.” U.S. Department of Health and Human Services. https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional (accessed April 2, 2018).


Without riboflavin, much of the food people eat could not be converted into energy. To produce energy, the body breaks down carbohydrates (starches and sugars) and fats into smaller units (glucose) that are then “burned” (oxidized) by cells to produce the energy they need to function. Riboflavin does not break down carbohydrates by itself. Instead, it joins with compounds called flavins that control the pathway that produces energy from food. Other vitamins such as B1 also are involved in this process. Riboflavin is especially important in supplying energy to muscles during physical activity and to the heart, which needs a continuous supply of energy.

When the body burns nutrients, free radicals are formed as a waste product of oxidation. Free radicals are highly reactive molecules that can damage cell membranes and DNA (genetic material). The damage that free radicals cause to cells is believed to play a role in the development of certain diseases, especially cancer. Riboflavin is an antioxidant. It binds to certain free radicals to neutralize them and remove them from the body so that they do not cause damage.

Riboflavin also plays a role in the way the body uses vitamin B6, niacin, folic acid, iron, and zinc. It helps convert vitamin B6 into its active form and is a necessary part of the chemical reactions that allow niacin to be used by the body. In the absence of riboflavin, less iron is absorbed from the intestines and the production of hemoglobin, the iron-containing molecule in red blood cells that transports oxygen around the body, is depressed.

Normal riboflavin requirements

The IOM has not set RDAs for riboflavin in children under one year old because of incomplete scientific information. Instead, it has set AI levels for this age group. No UL levels have been set for any age group because no negative (toxic) side effects have been found with large doses of riboflavin. RDAs for riboflavin are measured in milligrams (mg).

The following are the RDAs and AIs for riboflavin for healthy individuals:

Sources of riboflavin

People need a continuous supply of riboflavin from their diet because very little riboflavin is stored in the body; any excess is excreted in urine. Almost all healthy people in the United States get enough riboflavin from their diet and do not need to take a riboflavin supplement. In the United States starting in 1943, riboflavin, along with thiamin and niacin, has been added to flour. Other good sources of riboflavin include brewer's yeast, whole grains, wheat germ, and dark green vegetables. Some breakfast cereals are also fortified with riboflavin.

Exposure to light breaks down riboflavin in foods. For example, milk stored in a clear container and left in sunlight for two hours will lose about half of its riboflavin content. Foods containing riboflavin should be stored in opaque containers to prevent breakdown of the vitamin by light. Consumers should select milk in plastic cartons rather than glass bottles. Prolonged soaking or boiling also causes foods to lose riboflavin.

The following list gives the approximate riboflavin content for some common foods:

A molecule that prevents oxidation. In the body antioxidants attach to other molecules called free radicals and prevent the free radicals from causing damage to cell walls, DNA, and other parts of the cell.
Dietary supplement—
A product, such as a vitamin, mineral, herb, amino acid, or enzyme, that is intended to be consumed in addition to an individual's diet with the expectation that it will improve health.
A protein that changes the rate of a chemical reaction within the body without being depleted in the reaction.
A condition in which bilirubin, a waste product caused by the normal breakdown of red blood cells, builds up in the body faster than the liver can break it down. People with jaundice develop yellowish skin and the whites of their eyes become yellow. The condition can occur in newborns and people with liver damage.
A nutrient that the body needs in small amounts to remain healthy but that the body cannot manufacture for itself and must acquire through diet.
Water-soluble vitamin—
A vitamin that dissolves in water and can be removed from the body in urine.
Riboflavin deficiency

Symptoms of riboflavin deficiency tend to be fairly mild and include sore throat and tongue, cracked skin around the mouth and lips, skin inflammation, and eye problems such as excessive sensitivity to light, burning eyes, and gritty-feeling eyes. Some researchers also believe that migraine headaches may be triggered by riboflavin deficiency. Inadequate levels of riboflavin may decrease the body's ability to use iron, zinc, folic acid, vitamin B3 and vitamin B12.


Riboflavin appears to be safe in high doses and also safe during pregnancy. Extended use of high-dose riboflavin supplements may cause an imbalance with other water-soluble vitamins, especially vitamin B1.


Certain drugs appear to interfere with riboflavin's role in the chemical pathway that converts sugar to energy. These drugs include chlorpromazine and related antipsychotic drugs; tricyclic antidepressants; quinacrine, a drug used to prevent malaria; and doxorubicin (Adriamycin), a drug used in cancer chemotherapy. Long-term use of phenobarbital seems to increase the rate of destruction of riboflavin by the liver.


No complications are expected from riboflavin use. However, for most people, taking riboflavin as a high-dose dietary supplement does not provide any benefits.

Parental concerns

Parents should be aware that the riboflavin stores in newborns treated with light therapy for jaundice are rapidly depleted. Parents of these newborns should discuss the need for a short-term riboflavin supplement with their pediatrician.


See also Whole grains .



Berkson, Burt, and Arthur J. Berkson. Basic Health Publications User's Guide to the B-Complex Vitamins. Laguna Beach, CA: Basic Health, 2012.

Gaby, Alan R., and Healthnotes, eds. A–Z Guide to Drug-Herb-Vitamin Interactions: Improve Your Health and Avoid Side Effects When Using Common Medications and Natural Supplements Together. 2nd ed. New York: Three Rivers Press, 2006.

Lieberman, Shari, and Nancy Bruning. The Real Vitamin and Mineral Book: The Definitive Guide to Designing Your Personal Supplement Program. 4th ed. New York: Avery, 2007.

Zempleni, Janos, et al., eds. Handbook of Vitamins. 5th ed. Boca Raton, FL: Taylor & Francis, 2014.


Gill, Ranjodh Singh. “Riboflavin Deficiency.” Medscape. Updated August 9, 2016. http://emedicine.medscape.com/article/125193-overview (accessed April 17, 2018).

Higdon, Jane, Victoria J. Drake, and Barbara Delage. “Riboflavin.” Linus Pauling Institute, Oregon State University. http://lpi.oregonstate.edu/mic/vitamins/riboflavin (accessed April 17, 2018).

MedlinePlus. “Riboflavin.” U.S. National Library of Medicine, National Institutes of Health. https://medlineplus.gov/ency/article/002411.htm (accessed April 17, 2018).

U.S. Department of Agriculture, National Agricultural Library. “DRI Tables and Application Reports.” Food and Nutrition Information Center. https://www.nal.usda.gov/fnic/dri-tables-and-application-reports (accessed March 15, 2018).


Academy of Nutrition and Dietetics, 120 South Riverside Plz., Ste. 2000, Chicago, IL, 60606-6995, (312) 899-0040, (800) 877-1600, amacmunn@eatright.org, http://www.eatright.org .

Food and Nutrition Information Center, National Agricultural Library, 10301 Baltimore Ave., Rm. 105, Beltsville, MD, 20705, (301) 504-5414, Fax: (301) 504-6409, fnic@ars.usda.gov, http://fnic.nal.usda.gov .

Institute of Medicine, National Academy of Sciences, 500 Fifth St. NW, Washington, DC, 20001, (202) 334-2352, iomwww@nas.edu, http://www.iom.edu .

U.S. Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993-0002, (888) INFO-FDA (463-6332), http://www.fda.gov .

Tish Davidson, AM

  This information is not a tool for self-diagnosis or a substitute for professional care.