Riboflavin

Riboflavin (vitamin B2)

Contents of this page:
Background Synonyms Evidence Dosing	Safety Interactions

Riboflavin

Background

Riboflavin is a water-soluble vitamin, which is involved in vital metabolic processes in the body, and is necessary for normal cell function, growth, and energy production. Small amounts of riboflavin are present in most animal and plant tissues.

Healthy individuals who eat a balanced diet rarely need riboflavin supplements. Especially good dietary sources of riboflavin are milk (and other dairy products), eggs, enriched cereals/grains, meats, liver, and green vegetables (such as asparagus or broccoli). Intake may be lower in vegetarians compared to non-vegetarians.

Riboflavin is often used as a tracer of medication compliance in the treatment of patients with alcohol dependence, mental disorders, and other conditions. Urinary riboflavin levels may be measured in order to determine level of compliance.

Synonyms

7,8-dimethyl-10 (1'-D-ribityl) isoalloxazine, B-complex vitamin, Dolo-Neurotrat, flavin, flavine, lactoflavin, riboflavine, vitamin B2, vitamin G.

Supplements: The most common forms of riboflavin available in supplements are riboflavin and riboflavin 5'-monophosphate. Riboflavin is most commonly found in multivitamin and vitamin B-complex preparations.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence	Grade^*
Neonatal jaundice Riboflavin supplementation is included in the treatment of neonatal jaundice with phototherapy.	A
Riboflavin deficiency (ariboflavinosis) Studies suggest that riboflavin is beneficial in patients with riboflavin deficiency (ariboflavinosis). Ariboflavinosis may cause weakness, throat swelling/soreness, glossitis (tongue swelling) angular stomatitis/cheilosis (skin cracking or sores at the corners of the mouth), dermatitis (skin irritation), or anemia.Particular groups may be particularly susceptible to riboflavin deficiency, including the elderly, those with chronic illnesses, the poor, and those with alcohol dependency. Patients with suspected riboflavin deficiency should be evaluated by a qualified healthcare professional.	A
Anemia Some research suggests that riboflavin may play an adjunct role in the treatment of iron deficiency anemia and sickle cell anemia; levels of riboflavin may be low in these conditions. Correction of riboflavin deficiency in individuals who are both riboflavin deficient and iron deficient appears to improve response to iron therapy.	C
Anorexia / bulemia Levels of important nutrients are often low in individuals with anorexia or bulimia, with up to 20-33% of patients deficient in vitamins B2 (riboflavin) and B6 (pyridoxine). Dietary changes alone, without additional supplements, can often bring vitamin B levels back to normal. However, extra B2 and B6 may be required. Nutritional and medical guidance for such patients should be under the direction of a qualified healthcare professional.	C
Cataracts It has been suggested that low riboflavin levels may be a risk for developing cataracts, or that riboflavin supplementation may be beneficial for prevention. Additional evidence is needed before a clear conclusion can be drawn.	C
Cognitive function Adequate nutrient supplementation with riboflavin may be required for the maintenance of adequate cognitive function. Treatment with B-vitamins including riboflavin has been reported to improve scores of depression and cognitive function in patients taking tricyclic antidepressants. This may be related to tricyclic-caused depletion of riboflavin levels.	C
Depression Adequate nutrient supplementation with riboflavin may be required for the maintenance of adequate cognitive function. Treatment with B-vitamins, including riboflavin, has been reported to improve depression scores in patients taking tricyclic antidepressants. This may be related to tricyclic-caused depletion of riboflavin levels.	C
Esophageal cancer (prevention and treatment) Riboflavin supplementation has been studied in the prevention and treatment of esophageal cancer, mostly in China, with mixed results. No clear conclusion can be drawn at this time.	C
Ethylmalonic encephalopathy Although the exact pathogenesis of this disorder is unknown, some research suggests that riboflavin may lead to slight improvements in motor function, cognitive behavior, and diarrhea.	C
Malaria Low riboflavin levels have been associated with anti-malarial effects, and anti-riboflavin therapies were proposed in the 1980s, although more recent evidence has challenged this proposed association.	C
Migraine headache prevention Several studies suggest benefits of high-dose riboflavin in preventing migraine headaches.	C
Preeclampsia Limited study has reported an association between low riboflavin levels and an increased risk of preeclampsia (high blood pressure in pregnancy). However, it is not clear if low riboflavin levels are a cause or consequence of this condition, or if additional supplementation is warranted in pregnant women at risk of preeclampsia/eclampsia (beyond the routine use of prenatal vitamins).	C

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.

Grading rationale

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Acne, aging, alcohol dependence, ataxia, atherosclerosis, athletic performance, burning eyes, burning feet syndrome, burns, canker sores, carpal tunnel syndrome, cervical cancer, colon cancer, congenital methemoglobinemia, Crohn's disease, excess tearing, dermatitis, dementia, diabetes, digestion disorders, eczema, eye strain/fatigue, fatigue, glaucoma, glossitis, growth disorders, healthy hair, HIV, hypertension (high blood pressure), immune system function, keratoconus, lactic acidosis, leg cramps, liver disease, memory loss, mitochondrial disorders, mood disorders, mouth cancer, multiple acylcoenzyme A dehydrogenase deficiency, multiple sclerosis (MS), peptic ulcer disease (PUD), postoperative muscle cramps, neural tube defects, pain, red blood cell aplasia, reproduction disorders, rheumatoid arthritis, skin disorders, stress, stroke, ureteral colic pain, vitality problems.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Riboflavin Deficiency:

The U.S. Recommended Dietary Allowance (RDA) for riboflavin was revised in 1998, with the goal to prevent riboflavin deficiency. Clinical signs of deficiency in humans may appear at intakes less than 0.5-0.6 milligram per day, and excess urinary excretion of riboflavin can be seen at intake levels of approximately 1 milligram per day. Riboflavin deficiency (ariboflavinosis) can be associated with weakness, throat soreness/swelling, tongue swelling (glossitis), angular stomatitis/cheilosis (skin cracking or sores at the corners of the mouth), dermatitis (skin irritation), and anemia. Good dietary sources of riboflavin are milk (and other dairy products), eggs, enriched cereals/grains, meats, liver, and green vegetables (such as asparagus or broccoli). Riboflavin is easily destroyed by exposure to light (for example, riboflavin in milk stored in clear glass bottles).

Particular groups of people may be particularly susceptible to riboflavin deficiency, including the elderly, those with chronic illnesses, the poor, and those with alcohol dependence.

Adult Dosing (18 years and older):

The U.S. Recommended Dietary Allowance (RDA) for adults (by mouth) is 1 milligram for female adolescents (14-18 years old); 1.3 milligrams for male adolescents (14-18 years old); 1.1 milligrams for female adults (older than 18 years); 1.3 milligrams for male adults (older than 18 years); 1.4 milligrams for pregnant women (any age); 1.6 milligrams for breastfeeding women (any age).

Children Dosing (younger than 18 years):

The U.S. Recommended Dietary Allowance (RDA) for infants and children (by mouth) is 0.3 milligram for 0-6 months old; 0.4 milligram for 7-12 months old; 0.5 milligram for 1-3 years old; 0.6 milligram for 4-8 years old; 0.9 milligram for 9-13 years old; 1 milligram for female adolescents (14-18 years old); 1.3 milligrams for male adolescents (14-18 years old).

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Riboflavin supplementation has been associated with rare reports of allergy/anaphylaxis.

Side Effects and Warnings

In general, the limited capacity of human adults to absorb orally administered riboflavin limits its potential for harm. Riboflavin intake many times higher than the RDA is apparently without demonstrable toxicity. Nevertheless, the photosensitizing (sensitivity to light) properties of riboflavin raise the possibility of some potential risks. Other possible reactions to very high doses include itching, numbness, burning/prickling sensations, and yellow discoloration of the urine.

Very low birth weight infants who receive pre-term infant formulas (PIF) augmented to provide riboflavin at levels five times that in term infant formulas, have demonstrated high plasma levels of riboflavin and urinary riboflavin concentrations, and lower doses can be considered in this setting.

Pregnancy and Breastfeeding

Riboflavin is generally regarded as being safe during pregnancy and breastfeeding.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs:

Anticholinergic drugs may affect riboflavin absorption.

Low riboflavin levels have been associated with anti-malarial effects, and anti-riboflavin therapies were proposed in the 1980s, although more recent evidence has challenged this proposed association.

Doxorubicin (Adriamycin®) may deplete riboflavin levels.

Methotrexate may inhibit the effects of riboflavin in the body.

Early reports suggested that women taking high-dose oral contraceptives developed diminished riboflavin nutritional status, but when investigators controlled for dietary riboflavin intake, no impact was found.

Long-time use of phenobarbitol may increase destruction of riboflavin by liver enzymes, increasing the risk of deficiency.

Phenothiazine antipsychotic medications (e.g., chlorpromazine) may lower riboflavin levels.

Phenytoin (Dilantin®) may alter riboflavin levels.

Probenecid may decrease the absorption of riboflavin from the digestive tract and increase excretion in the urine.

There is preliminary evidence suggesting that postmenopausal breast cancer patients with low riboflavin levels will normalize their levels following treatment with tamoxifen. However, the cause of their baseline low riboflavin is unclear, and may be related to prior treatment with doxorubicin chemotherapy, a suspected cause of low riboflavin levels (which would likely recover with or without tamoxifen).

Riboflavin either alone or in combination with other B-vitamins should be taken at different times from tetracycline. In addition, long-term use of antibiotics can deplete vitamin B levels in the body (particularly B2, B9, B12, and biotin).

Thiazide diuretics may increase the loss of riboflavin in the urine.

Tricyclic antidepressants may reduce levels of riboflavin in the body, meriting supplementation. Treatment with B-vitamins, including riboflavin, has been reported to improve scores of depression and cognitive function in patients taking tricyclic antidepressants.

Interactions with Herbs and Dietary Supplements:

Severe riboflavin deficiency may impact multiple enzyme systems in the body, due to involvement in the metabolism of other vitamins including B6 (pyridoxine), B3 (niacin), and folate.