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Riboflavin (Monograph)

Drug class: Vitamin B Complex
ATC class: A11HA04
VA class: VT106
CAS number: 83-88-5

Medically reviewed by on Jul 22, 2022. Written by ASHP.


Water-soluble, B complex vitamin.

Uses for Riboflavin

Riboflavin Deficiency

Used to prevent and treat riboflavin deficiency (ariboflavinosis).

Riboflavin deficiency may occur in patients with long-standing infections, liver disease, alcoholism, malignancy, cardiac disease, diabetes mellitus, and those taking probenecid.

Dietary Requirements

Adequate intake needed to prevent riboflavin deficiency (ariboflavinosis).

Adequate intake of riboflavin usually can be accomplished through consumption of foodstuffs, including milk, bread products, and fortified cereals.

Estimated Average Requirement (EAR) and Recommended Dietary Allowance (RDA) in adults based on a combination of criteria including erythrocyte glutathione reductase activity and urinary excretion of riboflavin.

Adequate intake (AI) established for infants ≤6 months of age based on riboflavin intake of infants fed principally human milk; AI for infants 7–12 months of age based on the AI for younger infants and data from adults.

EAR and RDA for children 1–18 years of age based on data in adults.

Urinalysis Marker

Used as a urine marker when mixed with various drugs to test for patient compliance with the therapeutic regimen of these drugs.

Migraine Headaches

Has been used for prophylaxis of migraine headache [off-label] to decrease the frequency and duration of attacks.

Riboflavin Dosage and Administration


  • Correct poor dietary habits and consider a multivitamin preparation containing riboflavin in patients with vitamin deficiencies since poor dietary habits often result in concurrent deficiencies.


Administer orally.

May be given by IM injection or IV infusion as a component of a multivitamin injection. A parenteral formulation containing riboflavin alone is not currently commercially available.

Oral Administration

Administer orally, preferably with food.


Pediatric Patients

Riboflavin Deficiency (Ariboflavinosis)

Usually, 3–10 mg daily.

Dietary and Replacement Requirements

Infants <6 months of age: AI is 0.3 mg (0.04 mg/kg) daily.

Infants 6–12 months of age: AI is 0.4 mg (0.04 mg/kg) daily.

Children 1–3 years of age: RDA is 0.5 mg daily.

Children 4–8 years of age: RDA is 0.6 mg daily.

Children 9–13 years of age: RDA is 0.9 mg daily.

Girls 14–19 years of age: RDA is 1 mg daily.

Boys 14–19 years of age: RDA is 1.3 mg daily.


Riboflavin Deficiency (Ariboflavinosis)

Usually, 5–30 mg daily given in divided doses.

Patients with normocytic, normochromic anemia: 10 mg daily usually increases reticulocyte count within a few days.

Dietary and Replacement Requirements

Women ≥19 years of age: RDA is 1.1 mg daily.

Men ≥19 years of age: RDA is 1.3 mg daily.

These RDAs will not meet the needs of individuals with severe malabsorption.

Migraine Headaches† [off-label]

400 mg daily; maximal benefit may occur after 3 months of prophylaxis therapy.

Special Populations

Pregnant women: RDA is 1.4 mg daily. Riboflavin intake exceeding this RDA may be needed by women who are pregnant with more than one fetus.

Lactating women: RDA is 1.6 mg daily. Riboflavin intake exceeding this RDA may be needed by mothers nursing more than one infant.

May require additional riboflavin intake in patients who are extremely physically active.

Renal Impairment

Patients undergoing hemodialysis or peritoneal dialysis may require additional riboflavin.

Cautions for Riboflavin


  • Known hypersensitivity to riboflavin or any ingredient in the formulation.



Concomitant Diseases

Increased riboflavin deficiency risk in patients with cancer, cardiac disease, or diabetes mellitus.

General Precautions

Fixed-Combination Preparations

Consider the cautions, precautions, and contraindications associated with other drug(s) and vitamins in fixed-combination preparations.

Specific Populations


Category A. Category C (for dosages >RDA). (See Special Populations under Dosage and Administration.)


Distributed into human milk.

Common Adverse Effects

Usually nontoxic even in large doses.

Interactions for Riboflavin

Specific Drugs and Laboratory Tests

Drug or Test



Aminoglyosides (kanamycin, streptomycin)

Possible decreased antibiotic activity


Inactivated in vitro by riboflavin


Possible decreased antibiotic activity


Decreased absorption of riboflavin


Propantheline may delay the rate of riboflavin absorption, but increase the total amount absorbed

Spectrometry or color reaction urinalysis

Possible color interference

Tests for catecholamines

Possible false elevations in fluorometric determinations of plasma or urinary catecholamines

Tests for urobilinogen

Possible false elevations in fluorometric determinations of plasma or urinary urobilinogen

Riboflavin Pharmacokinetics



Readily absorbed from the upper GI tract. Rate of absorption is proportional to intake.


Therapeutic response in riboflavin-deficient patients may require several days for ocular and dermatologic manifestations of deficiency to improve.

Following oral administration in deficient patients with normocytic, normochromic anemia, an increase in reticulocyte count usually occurs within a few days.


Food increases extent of absorption.

Special Populations

Extent of absorption is decreased in patients with hepatitis, cirrhosis, or biliary obstruction.



Widely distributed into most tissues, including GI mucosal cells, erythrocytes, and the liver as riboflavin 5-phosphate (flavin mononucleotide [FMN]) and flavin adenine dinucleotide (FAD). Free riboflavin is present in the retina.

Stored in limited amounts in the liver, spleen, kidneys, and heart, mainly as FAD.

Crosses the placenta and is distributed into milk.

Plasma Protein Binding

About 60% as FAD and FMN.



Phosphorylated to FMN in GI mucosal cells, erythrocytes, and the liver; FMN is converted to FAD in the liver.

Elimination Route

Urine (about 9%) as unchanged drug; fate of the remainder of the dose not determined.


Following oral or IM administration, about 66–84 minutes.

Special Populations

Removal by hemodialysis is slower than normal renal excretion.

In neonates, urinary excretion is slow; however, the cumulative amount excreted is similar to the amount excreted by older infants.





Tight, light-resistant containers at 15–30°C.


For information on systemic interactions resulting from concomitant use, see Interactions.

Incompatible with alkaline solutions.


  • An exogenous source of riboflavin is required for tissue respiration.

  • Converts to coenzymes (FMN and FAD) involved in oxidation-reduction reactions of organic substrates and in intermediary metabolism.

  • Flavocoenzymes are involved in the formation of some vitamins and their coenzymes, including niacin, vitamin B6, and vitamin B12.

  • Indirectly involved in maintaining erythrocyte integrity.

Advice to Patients

  • Importance of proper dietary habits, including taking appropriate AI or RDA of vitamin B2.

  • Inform patients that large doses of riboflavin can result in bright yellow urine.

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.

  • Importance of informing patients of other important precautionary information. (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Riboflavin, riboflavin 5-phosphate, and riboflavin 5-phosphate sodium are also commercially available in combination with other vitamins, minerals, amino acids, cerebral stimulants, protein supplements, infant formulas, enzymes, hormones, sedatives, laxatives, and unsaturated fatty acids. For IM injection, riboflavin is commercially available in combination with other vitamins and iron. For IV infusion, riboflavin is commercially available in combination with other vitamins.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name



Dosage Forms


Brand Names






100 mg*


25 mg*

50 mg*

100 mg*



25 mg (as flavin mononucleotide [coenzymated])*

Riboflavin Sublingual Tablets

AHFS DI Essentials™. © Copyright 2023, Selected Revisions August 1, 2009. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

† Off-label: Use is not currently included in the labeling approved by the US Food and Drug Administration.

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