Riboflavin

Studies in people

• Benefit

  Women's fertility⁴

  In a large survey, women who ate more riboflavin were less likely to report infertility.

• Benefit

  Dementia risk in later life⁵

  In Japanese adults, eating more riboflavin was linked to fewer cases of disabling dementia.

• Open question

  Women's vitamin needs⁶

  Riboflavin is a vitamin women need more of during pregnancy and breastfeeding, and many women worldwide don't get enough.

• Benefit

  Heart and blood vessel risk⁷

  In people with a common gene variant, riboflavin lowered homocysteine, a blood marker linked to heart risk.

• Open question

  Movement problems in MS⁸

  In people with MS, riboflavin supplements and higher dietary riboflavin were linked to better movement, but one trial found no improvement.

• Benefit

  Stress and sleep¹⁰

  In a four-week trial, people taking riboflavin with vitamin B1 felt less stressed and slept better, though anxiety didn't improve.

• Benefit

  Constipation risk¹¹

  People who ate more riboflavin tended to have less constipation, though scientists do not yet know whether riboflavin causes this.

• Open question

  Mood and vitamin levels¹²

  In people with mood disorders, low riboflavin levels were found.

• Open question

  Infant vitamin levels¹³

  In Gambian babies, riboflavin levels were low at birth and stayed low without a supplement.

• Benefit

  Mental health in obesity¹⁴

  In people with obesity, those who ate more riboflavin tended to score better on a mental health questionnaire.

• Open question

  Vitamin levels in the body¹⁵

  In rural Gambians eating little, riboflavin supplements brought blood levels closer to normal, but scientists still question the target range.

• Open question

  Vitamin intake in older adults¹⁶

  About 80% of older Chinese adults may not get enough riboflavin from their food.

Animal and lab studies only

• Benefit

  Gut inflammation in mice²⁰

  In animal studies, riboflavin-producing bacteria and plain riboflavin both reduced intestinal damage in mice with gut inflammation.

Study type not stated

• Benefit

  Vitamin's role in disease prevention¹⁷

  Riboflavin may help protect against some cancers and other conditions, but scientists need more human studies to be sure.

• Benefit

  Antioxidant and brain disorders¹⁹

  Riboflavin is an antioxidant nutrient that may prevent lipid peroxidation and may help in some brain problems.

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

• Severe allergic reaction to a vitamin⁹

  A boy had a severe allergic reaction after drinking a soft drink or taking a multivitamin containing riboflavin.

How it’s made and used

• Vitamin deficiency signs²

  Not getting enough riboflavin can cause anaemia, high blood pressure and skin and mouth problems.

• How the body absorbs it³

  Riboflavin is taken in through the gut, and not getting enough affects iron absorption and other body processes.

• Anemia risk¹⁸

  Diets low in riboflavin may make anemia more likely when iron intake is also low.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.

Expert panels that weigh all the research. Shown for context: the signal at the top does not count them.

• UN and WHO food additive experts (JECFA), 2021

  No daily limit needed (“ADI not specified”, JECFA’s term for very low toxicity).