[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Vitamins](https://durgical.com/en/pharmacology/classes/vitamins/) › Riboflavin

# Riboflavin

## Vitamins?

Vitamins

Vitamin B2, the building block of the coenzymes FMN and FAD. Deficiency causes sores at the mouth corners, a sore tongue and anaemia.

Updated Nov 1, 2026

Also called: vitamin B2

## Quick facts

**Group**
[Vitamins](https://durgical.com/en/pharmacology/classes/vitamins/)

**Target**
Precursor of FMN and FAD, the flavin coenzymes

**Used for**
Riboflavin deficiency

**Key effects**
No known toxicity from riboflavin

**Monitor**
Mouth · Blood count if anaemia is present

**ATC**
A11HA04

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

Riboflavin is turned into flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which carry electrons in the release of energy from carbohydrates, fats and proteins. FAD is also needed to activate vitamin B6. Deficiency usually comes with other B-vitamin deficiencies.

- Riboflavin → FMN and FAD
- Flavins carry electrons in energy metabolism
- FAD also helps activate vitamin B6

## Indications

- Riboflavin deficiency, usually with other B-vitamin deficiencies

## Adverse effects

- No known toxicity from riboflavin

## Contraindications

- Hypersensitivity to the product

## Key interactions

**Pyridoxine (vitamin B6)**
Riboflavin is needed to convert pyridoxine to its active form

## What is monitored

- Mouth, lips, tongue and skin in deficiency
- Blood count if anaemia is present

## Administration and safety

- Riboflavin is destroyed by light: products and foods are kept out of clear, sunlit containers.

## Pregnancy and breastfeeding

Riboflavin is needed in pregnancy; no harm is known at nutritional amounts.

## Nursing care

- Look for other B-vitamin deficiencies when riboflavin deficiency is suspected.
- Ask about diet: dairy, eggs, meat, green leafy vegetables and fortified cereals.

## Pharmacokinetics

**Absorption**
Absorbed by mouth; water-soluble

**Elimination**
Amounts the body does not need leave in the urine

## Memory aid

«B2 = 2 coenzymes, FMN and FAD»: lack of them cracks the corners of the mouth.

## Test yourself

Think of the answer, then tap the question to see it.

## Which two coenzymes are made from riboflavin?

FMN and FAD.

## Why can riboflavin deficiency worsen vitamin B6 status?

Riboflavin is needed to convert pyridoxine into its active coenzyme.

## What happens to riboflavin exposed to light?

It is destroyed.

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## Connections

## Related drugs 3

- [Pyridoxine](https://durgical.com/en/pharmacology/pyridoxine/)
- [Thiamine](https://durgical.com/en/pharmacology/thiamine/)
- [Nicotinamide](https://durgical.com/en/pharmacology/nicotinamide/)

[← Back to the class: Vitamins](https://durgical.com/en/pharmacology/classes/vitamins/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Riboflavin: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/002411.htm) (MedlinePlus (U.S. National Library of Medicine), 2026); [DailyMed - PYRIDOXINE HYDROCHLORIDE injection, solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a56d11c0-b033-4201-85ff-fc710506481a) (DailyMed (U.S. National Library of Medicine), 2019); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=A11HA04) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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