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.
Riboflavin’s functions include:
Assisting in energy productionHelping to synthesize normal fatty acids and amino acidsHelping the nervous system to function efficientlyAiding in cellular growthAssisting 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 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 mouthSore or inflamed tongue (glossitis)Reddening of the eyesEyes that tire easily, burn, itch, or are sensitive to lightUnusual skin inflammation (dermatitis) characterized by simultaneous dryness and greasy scaling
Riboflavin 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.
|Food||Serving size||Riboflavin content|
|Beef, cooked||3 ounces||0.15 milligrams (mg)|
|Broccoli, cooked||½ cup||0.1 mg|
|Spinach, cooked||½ cup||0.21 mg|
|Milk, skim||1 cup||0.45 mg|
|Egg||1 large||0.26 mg|
|Whole wheat bread||1 slice||0.06 mg|
The following populations may be at risk for riboflavin deficiency and may require a supplement:
People who consume excessive amounts of
alcoholPeople with other nutrient deficiencies
Evidence 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.
Talk 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.
To 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:
EggsAlmondsLeafy green vegetablesMilkEnriched cerealMeats
Riboflavin is rapidly destroyed with exposure to sunlight. Therefore, foods containing riboflavin are best stored in a pantry, in bins, and, when perishable, in the refrigerator.
Migraine prophylaxis in adults. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated January 9, 2015. Accessed February 11, 2015.
Riboflavin. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated January 8, 2013. Accessed February 11, 2015.
Riboflavin deficiency. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated January 20, 2011. Accessed February 11, 2015.
Riboflavin. The Linus Pauling Institute website. Available at:
Updated July 2013. Accessed February 11, 2015.
Sperduto RD, Hu TS, 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/biomedical-libraries/natural-alternative-treatments. Updated September 18, 2014. Accessed February 11, 2015.
Last reviewed February 2015 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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