Vitamin B2: Riboflavin
Vitamin B2, also called riboflavin, is a water-soluble vitamin. Water-soluble vitamins are stored in the body in very limited amounts and are excreted through the urine. Therefore, it is a good idea to have them in your daily diet. Vitamin B2 is a component of two enzymes: flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). These coenzymes are important in energy production.
FunctionsRiboflavin’s functions include:
- Assisting in energy production
- Helping to synthesize normal fatty acids and amino acids
- Helping the nervous system to function efficiently
- Aiding in cellular growth
- Assisting in the metabolism of certain other vitamins
|Age Group (in years)||Recommended Dietary Allowance|
|1-3||0.5 milligrams (mg)||0.5 mg|
|4-8||0.6 mg||0.6 mg|
|9-13||0.9 mg||0.9 mg|
|14-18||1.0 mg||1.3 mg|
|19+||1.1 mg||1.3 mg|
Riboflavin DeficiencyRiboflavin deficiency occurs as part of multiple nutrient deficiency states. Since riboflavin occurs in a wide variety of foods, deficiency symptoms are rare. Symptoms have been reported when daily riboflavin intake falls below 0.6 milligrams (mg). Symptoms of riboflavin deficiency include:
- Cracks in the corner of the mouth (cheilosis)
- Inflammation of the mucous membranes of the mouth
- Sore or inflamed tongue (glossitis)
- Reddening of the eyes
- Eyes that tire easily, burn, itch, or are sensitive to light
- Unusual skin inflammation (dermatitis) characterized by simultaneous dryness and greasy scaling
Riboflavin ToxicityRiboflavin is relatively nontoxic. Although no adverse effects have been associated with high intakes of riboflavin from food or supplements, the potential may exist. Therefore, caution may be warranted with excessive amounts of riboflavin.
Major Food Sources
|Food||Serving size||Riboflavin content|
|Beef, cooked||3 ounces||0.16 milligrams (mg)|
|Broccoli, cooked||½ cup||0.1 mg|
|Spinach, cooked||½ cup||0.21 mg|
|Milk, skim||1 cup||0.34 mg|
|Egg||1 large||0.27 mg|
|Whole grain bread||1 slice||0.06 mg|
Populations at Risk for Riboflavin DeficiencyThe following populations may be at risk for riboflavin deficiency and may require a supplement:
- People who consume excessive amounts of alcohol
- People with other nutrient deficiencies
- People with anorexia nervosa
Prevention of CataractsEvidence that links riboflavin to the prevention of cataracts is unclear. Two large studies showed decreases in cataract rates in people over 65 years taking multivitamins, minerals, riboflavin, and riboflavin with niacin. Although the studies showed decreased risk of cataracts, the mixing of the vitamins made it difficult to tell which supplement caused the benefits.
Treatment of Migraine HeadachesTalk to your doctor about using riboflavin supplements if you have migraine headaches. In some adults, 400 mg per day may prevent migraines or reduce the number of migraine attacks.
Tips for Increasing Your IntakeTo help increase your intake of riboflavin, include some dairy products in your daily diet. Milk, yogurt, and cheese are all good sources of riboflavin. Here are some other examples of foods with riboflavin:
- Leafy green vegetables
- Enriched cereal
Academy of Nutrition and Dietetics
United States Department of Agriculture
Dietitians of Canada
Health Canada Food and Nutrition
DiDonato S, Geller, C, Peluchetti D, et al. Normalization of short-chain acylcoenzyme A dehydrogenase after riboflavin treatment in a girl with multiple acylcoenzyme A dehydrogenase-deficient myopathy. Ann Neurol. 1989;25:479-484.
Migraine prophylaxis in adults. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php. UpdatedNovember 19, 2012. Accessed February 7, 2013
Riboflavin. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php. Updated May 16, 2011. Accessed February 7, 2013.
Riboflavin deficiency. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php. Updated January 20, 2011. Accessed February 7, 2013
Riboflavin. The Linus Pauling Institute website. Available at: http://lpi.oregonstate.edu/infocenter/vitamins/riboflavin/. Updated June 2007. Accessed February 7, 2013.
Sperduto RD, Hu TS, Milton RC, et al. The Linxian cataract studies. Two nutrition intervention trials.Arch Ophthalmol. 1993;111(9):1246-1253.
Vitamin B2. EBSCO Natural and Alternative Treatments website. Available at: http://www.ebscohost.com/healthlibrary. Updated July 25, 2012. Accessed February 7, 2013.
- Reviewer: Brian Randall, MD
- Review Date: 02/2013
- Update Date: 02/07/2013