Riboflavin

Riboflavin, or vitamin B2, is a water-soluble vitamin the body uses to release energy from carbohydrates, protein, and fat and to support normal cell growth and red blood cell production. Like other B vitamins it isn't stored in large amounts, so regular intake matters. Organ meats, dairy, eggs, and fortified grains supply most of it in a typical diet.

What is riboflavin

Riboflavin is a coenzyme component the body uses across a wide range of metabolic reactions — Harvard T.H. Chan School of Public Health, The Nutrition Source describes it as central to cell growth, energy production, and the breakdown of fats, steroid compounds, and some medications. The body uses most dietary riboflavin promptly rather than storing it, excreting any excess in urine, and it is notably sensitive to light — MedlinePlus notes riboflavin is destroyed by light exposure, which is why milk is sold in opaque containers rather than clear glass. Harvard's Nutrition Source lists dairy products, eggs, lean meats, organ meats, chicken, salmon, fortified cereals and breads, and almonds as primary sources. In this project's data, the most concentrated non-fortified sources by measured amount are beef liver, spirulina, and chicken liver, with almonds and salmon among the more everyday whole-food sources.

Health benefits of riboflavin

• Energy metabolism. Riboflavin's foundational, well-established role is as a coenzyme in the pathways that release energy from carbohydrate, protein, and fat, and it supports red blood cell production, per MedlinePlus.
• Migraine prevention (evidence is dose-specific, not a general "take riboflavin" recommendation). Harvard's Nutrition Source reports that a systematic review found a modest reduction in migraine frequency in adults and children at riboflavin doses of roughly 400 mg/day for adults and 200 mg/day for children, taken for about three months — far above ordinary dietary intake and squarely in supplement territory. The American Academy of Neurology and American Headache Society concluded riboflavin is "probably effective for preventing migraine headaches" at those doses, per the same source. This is evidence about high-dose supplementation for a specific condition, not a claim that dietary riboflavin intake prevents migraines.
• Cardiovascular disease — not a supported use. Harvard's Nutrition Source notes that despite riboflavin's theoretical role in homocysteine metabolism, the American Heart Association does not recommend B-vitamin supplements for reducing cardiovascular disease risk.

How much you need

The NIH Office of Dietary Supplements sets the RDA for riboflavin, corroborated by Harvard's Nutrition Source (directly fetched), at 1.3 mg/day for adult men and 1.1 mg/day for adult women, rising to 1.4 mg/day during pregnancy and 1.6 mg/day during lactation. No Tolerable Upper Intake Level (UL) has been established: Harvard's Nutrition Source states that no toxic level has been observed from food or supplements, attributing this to limited intestinal absorption and rapid urinary excretion of any excess. These figures are not yet populated in this project's own nutrient_rda table.

Signs of deficiency and excess

Isolated riboflavin deficiency (ariboflavinosis) is uncommon in the United States today. When it occurs, MedlinePlus lists anemia, mouth and lip sores, sore throat, and swelling of mucous membranes; Harvard's Nutrition Source adds cracked lips, glossitis (a swollen, inflamed tongue), hair loss, skin rash, and itchy, red eyes, with cataracts described as a possible consequence of more severe, prolonged deficiency. Riboflavin deficiency rarely occurs alone — it is often accompanied by shortfalls in other B vitamins, since diets low in one B vitamin are typically low in several. No toxicity or excess signs are documented for riboflavin, consistent with the lack of an established UL.

Warnings & interactions

Riboflavin at typical dietary and standard supplement intakes has no well-documented drug interactions or upper-limit toxicity concerns on the trusted sources reviewed for this page. The one caution worth naming explicitly is about expectations, not safety: Harvard's Nutrition Source is direct that the American Heart Association does not recommend B-vitamin supplementation, including riboflavin, as a strategy for lowering cardiovascular disease risk, despite riboflavin's role in homocysteine-related metabolism. The migraine-prevention doses studied in clinical trials (around 400 mg/day for adults) are far above the RDA and were used under research/clinical conditions — that gap is worth being clear about rather than presenting high-dose supplementation as equivalent to normal dietary intake.

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