Uses of this Supplement
Carpal Tunnel Syndrome
Headache, Migraine
Rheumatoid Arthritis
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Look Up > Supplements > Vitamin B2 (Riboflavin)
Vitamin B2 (Riboflavin)
Dietary Sources
Commercial Preparations
Therapeutic Uses
Dosage Ranges and Duration of Administration
Side Effects/Toxicology


Riboflavin is a water-soluble, heat-stable vitamin. It is a component of two flavin coenzymes, flavin-adenine dinucleotide (FAD) and flavin mononucleotide (FMN). These coenzymes are intermediaries in electron transport in many oxidative-reduction reactions throughout the body. Riboflavin is essential to tissue respiration and to the generation of energy metabolism from carbohydrates, proteins, and fats. Riboflavin is necessary for normal development and repair of the immune system and of body tissues such as skin, hair, nails, and connective tissue. Recent studies suggest that riboflavin may be an effective low-cost preventive treatment for migraine headaches. A proposed mechanism for this effect suggests that migraines result from a reduction of energy production in the mitochondria, and riboflavin increases mitochondrial energy efficiency. In a 1998 study from Belgium, patients who suffered from migraines were given 400 mg of riboflavin a day for three months. Other patients also received a daily dose of aspirin. Fifty-nine percent of patients in the riboflavin groups showed at least a 50% improvement compared to 15% in the placebo group.

Animal studies suggest that elevated riboflavin levels protect against oxidative damage. Studies have shown reduced myocardial damage after an ischemic event, prevention of nerve damage after stroke, and minimization of oxidative damage resulting from the introduction of toxins.

Riboflavin supplements may help in the treatment of sickle-cell anemia. They may also help in the treatment of anemia by enhancing the efficacy of iron.

Riboflavin, in combination with vitamin B6, helps relieve the symptoms of carpal tunnel syndrome.

Some studies suggest that riboflavin abnormalities are associated with cataract development. A New York State Lens Opacities Case-Control Study evaluated the risk factors for various types of cataracts. Among the 1,380 participants (ages 40 to 79 years), they found that the risk for cataracts increased if the levels of certain nutrients, including riboflavin, were low. Glutathione, an enzyme that helps protect the eye, requires riboflavin to work effectively. Other studies have suggested no relationship between riboflavin and cataracts; some studies suggest that high-dose riboflavin can induce cataracts. Thirty-three percent of the geriatric population has riboflavin deficiency. High-level supplementation in this population, however, may be contraindicated.

A recent study evaluated the links between rheumatoid arthritis and riboflavin status in individuals with and without the disease. Biochemical riboflavin deficiency was more frequent in those with active disease. Riboflavin deficiency may reduce the activity and effect of glutathione, an enzyme that works to prevent inflammation involved in rheumatoid arthritis.

Frank deficiency of riboflavin is rare. However, subclinical deficiency is common in certain populations, including those with lactose intolerance, malabsorptive disorders, diarrhea, and irritable bowel syndrome. The elderly, whose diets are low in red meats and dairy products, may also be at risk for mild riboflavin deficiency. Systemic infection, with or without gastrointestinal tract involvement, may increase the body's need for riboflavin. Symptoms of riboflavin deficiency include cracking of lips and corner of the mouth, swollen, inflamed tongue, visual disturbances such as sensitivity to light and cataract formation, anemia, and dermatitis.

Dietary Sources
  • Brewer's yeast
  • Almonds
  • Organ meats
  • Whole grains
  • Wheat germ
  • Wild rice
  • Mushrooms
  • Soybeans
  • Milk
  • Spinach

Flours and cereals are enriched with riboflavin. Riboflavin is destroyed by light and alkalis, but not by heat, although it will leach into cooking water. To retain riboflavin content, foods should be stored in dark containers.


Riboflavin supplements are available in two forms: simple riboflavin or riboflavin-5-phosphate (the activated form).

Commercial Preparations

Riboflavin is available in multivitamin preparations, in B-complex vitamins, and as riboflavin and activated riboflavin, in 25-, 50-, and 100-mg tablets.

Therapeutic Uses
  • Indicated for sickle-cell anemia
  • Preventive measure for migraine headaches
  • May relieve symptoms of rheumatoid arthritis
  • May be useful in treating cataracts secondary to deficiency
  • Part of therapy to relieve symptoms of carpal tunnel syndrome
  • Reduces the effects of stress
  • Skin problems such as acne (especially acne rosacea), dermatitis, eczema, and ulcers may improve with supplementation
  • May improve muscle cramps
  • Indicated when initiating any B vitamin supplementation
  • Enhances immune function
  • Preventive against free radical damage

Dosage Ranges and Duration of Administration

RDA for riboflavin is listed below.

  • Children 1 to 3 years: 0.5 mg/day
  • Children 4 to 8 years: 0.6 mg/day
  • Children 9 to 13 years: 0.9 mg/day
  • Men 14 years and older: 1.3 mg/day
  • Women 14 to 19 years: 1.0 mg/day
  • Women over 19 years: 1.2 mg/day
  • Women during pregnancy: 1.4 mg/day
  • Women during lactation: 1.6 mg/day

Side Effects/Toxicology

The body does not absorb high doses (>20 mg) of riboflavin well, making toxicity rare. Reactions to excess doses may include itching, numbness, burning or prickling sensations, and sensitivity to light.


Urine will become discolored with high doses of riboflavin. This can affect urinalysis results.


Supplementation with vitamins B1, B2, and B6 (10 mg each) at the start of tricyclic antidepressant therapy improved cognitive functioning and depression ratings in 14 geriatric patients undergoing treatment with nortriptyline titrated to doses yielding blood levels between 50 to 150 ng/mL (Bell, et al. 1992). B vitamins may augment the treatment of depression in elderly patients.


Children receiving the anticonvulsant drug diphenylhydantoin have displayed subnormal urinary excretions of riboflavin (Lewis et al. 1975).


In one study, the bioavailability of tetracycline hydrochloride was reduced significantly by concomitant administration of vitamin B complex to healthy subjects (Omray 1981). Patients should be cautioned to take vitamin B complex supplements at different times from tetracycline.


Bell, IR, Edman JS, Morrow FD, et al. Brief communication. Vitamin B1, B2, and B6 augmentation of tricyclic antidepressant treatment in geriatric depression with cognitive dysfunction. J Am Coll Nutr. 1992;11(2):159-163.

Christenson H. Riboflavin can protect tissues from oxidative injury. Nutr Rev. May 1993;51:149-150.

Drug Facts and Comparisons 1999. New York, NY: J.B. Lippincott Company; 1998.

Duyff R. The American Dietary Association Complete Food and Nutrition Guide. Minneapolis, Minn: Cronimed Publishing; 1996.

Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 1998.

Lewis JA, Baer MT, Laufer MA. Urinary riboflavin and creatinine excretion in children treated with anticonvulsant drugs [letter]. Am J Dis Child. 1975;129:394.

Matarese L, Gottschlich M. Contemporary Nutrition Support Practice: A Clinical Guide. Philadelphia, Pa: WB Saunders Co; 1998.

Murray MT. Encyclopedia of Nutritional Supplements. Rocklin, Calif: Prima Health; 1996.

Omray A. Evaluation of pharmacokinetic parameters of tetracylcine hydrochloride upon oral administration with vitamin C and vitamin B complex. Hindustan Antibiot Bull. 1981;23(VI):33-37.

Realey N. Vitmains Etc. Melbourne, Australia: Bookman Press; 1998.

Schoenen J, Jacquy J, Lenaerts M. Effectiveness of high-dose riboflavin in migraine prophylaxis: a randomized controlled trial. Neurology. February 1998;50:466-470.

Copyright © 2000 Integrative Medicine Communications

This publication contains information relating to general principles of medical care that should not in any event be construed as specific instructions for individual patients. The publisher does not accept any responsibility for the accuracy of the information or the consequences arising from the application, use, or misuse of any of the information contained herein, including any injury and/or damage to any person or property as a matter of product liability, negligence, or otherwise. No warranty, expressed or implied, is made in regard to the contents of this material. No claims or endorsements are made for any drugs or compounds currently marketed or in investigative use. The reader is advised to check product information (including package inserts) for changes and new information regarding dosage, precautions, warnings, interactions, and contraindications before administering any drug, herb, or supplement discussed herein.