Riboflavin (Vitamin B2)

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What other names is Riboflavin known by?

B Complex Vitamin, Complexe de Vitamines B, Flavin, Flavine, Lactoflavin, Lactoflavine, Riboflavina, Riboflavine, Vitamin B-2, Vitamin G, Vitamina B2, Vitamine B2, Vitamine G.

What is Riboflavin?

Riboflavin is a B vitamin. It can be found in certain foods such as milk, meat, eggs, nuts, enriched flour, and green vegetables. Riboflavin is frequently used in combination with other B vitamins in vitamin B complex products. Vitamin B complex generally includes vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin/niacinamide), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B12 (cyanocobalamin), and folic acid. However, some products do not contain all of these ingredients and some may include others, such as biotin, para-aminobenzoic acid (PABA), choline bitartrate, and inositol.

Riboflavin is used for preventing low levels of riboflavin (riboflavin deficiency), cervical cancer, and migraine headaches. It is also used for treating riboflavin deficiency, acne, muscle cramps, burning feet syndrome, carpal tunnel syndrome, and blood disorders such as congenital methemoglobinemia and red blood cell aplasia. Some people use riboflavin for eye conditions including eye fatigue, cataracts, and glaucoma.

Other uses include increasing energy levels; boosting immune system function; maintaining healthy hair, skin, mucous membranes, and nails; slowing aging; boosting athletic performance; promoting healthy reproductive function; canker sores; memory loss, including Alzheimer's disease; ulcers; burns; alcoholism; liver disease; sickle cell anemia; and treating lactic acidosis brought on by treatment with a class of AIDS medications called NRTI drugs.

Effective for...

  • Preventing and treating riboflavin deficiency and conditions related to riboflavin deficiency.

Possibly Effective for...

  • Cataracts, an eye disorder. People who eat more riboflavin as part of their diet seems to have a lower risk of developing cataracts. Also, taking supplements containing riboflavin plus niacin seems to help prevent cataracts.
  • High amounts of homocysteine in the blood (hyperhomocysteinemia). Some people are unable to convert the chemical homocysteine into the amino acid methionine. People with this condition, especially those with low riboflavin levels, have high amounts of homocysteine in the blood. Taking riboflavin for 12 weeks seems to reduce homocysteine levels by up to 40% in some people with this condition. Also, certain antiseizure drugs can increase homocysteine in the blood. Taking riboflavin along with folic acid and pyridoxine seems to lower homocysteine levels by 26% in people with high homocysteine levels due to antiseizure drugs.
  • Migraine headaches. Taking high-dose riboflavin (400 mg/day) seems to significantly reduce the number of migraine headache attacks. However, taking riboflavin does not appear to reduce the amount of pain or the amount of time a migraine headache lasts. Also, taking lower doses of riboflavin (200 mg/day) does not seem to reduce the number of migraine headache attacks.

Possibly Ineffective for...

  • Stomach cancer. Taking riboflavin along with niacin does not seem to help prevent gastric cancer.
  • Malnutrition caused by too little protein in the diet (kwashiorkor). Some research suggests that taking riboflavin, vitamin E, selenium, and N-acetyl cysteine does not reduce the buildup of fluid in the tissues, increase height or weight, or reduce infections in children at risk for kwashiorkor.
  • Lung cancer. Taking riboflavin along with niacin does not seem to help prevent lung cancer.
  • Malaria. Taking riboflavin along with iron, thiamine, and vitamin C does not seem to reduce the number or severity of malaria infections in children at risk of being exposed to malaria.
  • High blood pressure during pregnancy (pre-eclampsia). Taking riboflavin beginning at about 4 months gestation does not seem to reduce the risk of pre-eclampsia.

Insufficient Evidence to Rate Effectiveness for...

  • Lactic acidosis (a serious blood-acid imbalance) in people with acquired immunodeficiency syndrome (AIDS). There is preliminary clinical evidence that riboflavin may be useful for treating lactic acidosis in patients with acquired immunodeficiency syndrome (AIDS) caused by drugs called nucleoside analog reverse transcriptase inhibitors (NRTI).
  • Preventing cervical cancer. There is evidence that increasing riboflavin intake from dietary and supplement sources, along with thiamine, folic acid, and vitamin B12, might decrease the risk of developing precancerous spots on the cervix.
  • Cancer of the food pipe (esophageal cancer). Research on the effects of riboflavin for preventing esophageal cancer is conflicting. Some research shows that taking riboflavin as a supplement or as part of the diet is linked with a reduced risk for esophageal cancer. However, other research shows that taking riboflavin, alone or along with calcium or niacin, does not help prevent esophageal cancer.
  • Liver cancer. Early research suggests that taking riboflavin along with niacin might reduce the risk of liver cancer in people less than 55 years-old. However, it does not seem to reduce the risk of liver cancer in older people.
  • White patches inside the mouth (oral leukoplakia). Early research suggests that low blood levels of riboflavin are linked with an increased risk of oral leukoplakia. However, taking riboflavin supplements for 20 months does not seem to prevent or treat oral leukoplakia.
  • Iron deficiency during pregnancy. Early research suggests that taking riboflavin along with iron and folic acid does not improve iron levels in pregnant women better than taking iron and folic acid.
  • Sickle cell disease. Early research suggests that taking riboflavin for 8 weeks improves iron levels in people with low iron levels due to sickle cell disease. However, riboflavin does not seem to improve levels of hemoglobin, the iron-containing protein in the blood.
  • Stroke. Early research suggests that taking riboflavin along with niacin does not prevent stroke-related death in people at risk for stroke.
  • Acne.
  • Muscle cramps.
  • Boosting the immune system.
  • Aging.
  • Maintaining healthy skin and hair.
  • Canker sores.
  • Memory loss including Alzheimer's disease.
  • Other conditions.
More evidence is needed to rate the effectiveness of riboflavin for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

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How does Riboflavin work?

Riboflavin is required for the proper development and function of the skin, lining of the digestive tract, blood cells, and many other parts of the body.

Are there safety concerns?

Riboflavin is LIKELY SAFE for most people when taken by mouth. In some people, riboflavin can cause the urine to turn a yellow-orange color. When taken in high doses, riboflavin might cause diarrhea, an increase in urine, and other side effects.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Riboflavin is LIKELY SAFE for pregnant or breast-feeding women when taken in the amounts recommended. The recommended amounts are 1.4 mg per day for pregnant women and 1.6 mg per day in breast-feeding women. Riboflavin is POSSIBLY SAFE when taken by mouth in larger doses, short-term. Some research shows that riboflavin is safe when taken at a dose of 15 mg once every 2 weeks for 10 weeks.

Hepatitis, Cirrhosis, Billary obstruction: Riboflavin absorption is decreased in people with these conditions.

Are there any interactions with medications?



Antibiotics (Tetracycline antibiotics)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Riboflavin might decrease the amount of tetracyclines that the body can absorb. Taking riboflavin along with tetracyclines might decrease the effectiveness of tetracyclines. To avoid this interaction, take riboflavin 2 hours before or 4 hours after taking tetracyclines.

Some tetracyclines include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin).



Drying medications (Anticholinergic drugs)
Interaction Rating: Minor Be cautious with this combination.
Talk with your health provider.

Some drying medications can affect the stomach and intestines. Taking these drying medications with riboflavin (vitamin B2) can increase the amount of riboflavin that is absorbed in the body. But it's not known if this interaction is important.



Medications for depression (Tricyclic antidepressants)
Interaction Rating: Minor Be cautious with this combination.
Talk with your health provider.

Some medications for depression can decrease the amount of riboflavin in the body. This interaction is not a big concern because it only occurs with very large amounts of some medications for depression.



Phenobarbital (Luminal)
Interaction Rating: Minor Be cautious with this combination.
Talk with your health provider.

Riboflavin is broken down by the body. Phenobarbital might increase how quickly riboflavin is broken down in the body. It is not clear if this interaction is significant.



Probenecid (Benemid)
Interaction Rating: Minor Be cautious with this combination.
Talk with your health provider.

Probenecid (Benemid) can increase how much riboflavin is in the body. This might cause there to be too much riboflavin in the body. But it's not known if this interaction is a big concern.

Dosing considerations for Riboflavin.

The following doses have been studied in scientific research:

BY MOUTH:
  • For treating low levels of riboflavin (riboflavin deficiency) in adults: 5-30 mg of riboflavin (Vitamin B2) daily in divided doses.
  • For preventing migraine headaches: 400 mg of riboflavin (Vitamin B2) per day. It may take up to three months to get best results.
  • For preventing cataracts: a daily dietary intake of approximately 2.6 mg of riboflavin (Vitamin B2) has been used. A combination of 3 mg of riboflavin (Vitamin B2) plus 40 mg of niacin daily has also been used.
  • The daily recommended dietary allowances (RDAs) of riboflavin (Vitamin B2) are: Infants 0-6 months, 0.3 mg; infants 7-12 months, 0.4 mg; children 1-3 years, 0.5 mg; children 4-8 years, 0.6 mg; children 9-13 years, 0.9 mg; men 14 years or older, 1.3 mg; women 14-18 years, 1 mg; women over 18 years, 1.1 mg; pregnant women, 1.4 mg; and breastfeeding women, 1.6 mg.
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Reviewed on 3/29/2011 12:35:40 PM

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