Riboflavin (B2)

Water-soluble · energy

What does Riboflavin (B2) do in your body?

Part of FAD and FMN, coenzymes that carry electrons in energy production. It's why some vitamin pills turn urine bright yellow.

What does Riboflavin (B2) do?

Forms coenzymes used in energy production and in activating other B vitamins (B6, niacin, folate).

Where does Riboflavin (B2) act in the body?

Mitochondria in every cell.

Which foods contain Riboflavin (B2)?

Milk and yogurt, eggs, lean meats, mushrooms, almonds, fortified cereals.

How much Riboflavin (B2) do adults need?

RDA: 1.3 mg (men), 1.1 mg (women). No upper limit set.

What happens with too little Riboflavin (B2)?

Rare; can cause cracked lips, sore throat and skin changes.

Can you get too much Riboflavin (B2)?

No toxicity known. Excess is excreted, coloring urine bright yellow — harmless.

What does Riboflavin (B2) interact with?

Needed to activate vitamin B6 and niacin.

What is known and unknown about Riboflavin (B2)?

Coenzyme roles are established.

Evidence & sources

• The adult RDA for riboflavin is 1.3 mg (men) and 1.1 mg (women). Evidence: regulatory. Known: Set by the Institute of Medicine (1998). Unknown: — Source: NIH Office of Dietary Supplements, Riboflavin — Health Professional Fact Sheet (Current revision).

Connected topics

• Energy Metabolism
• Vitamin B6
• Niacin (B3)
• Milk

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General education only, not medical advice. Drafted Oct 2026 · pending qualified expert review.