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Riboflavin (B2)

Vitamin Unit: mg

B vitamin (B2) needed for energy production, cell function, and metabolism of fats and drugs.

Recommended Daily Allowance (RDA)

1.3
Adult Male
mg/day
1.1
Adult Female
mg/day
Daily Requirements by Life Stage 16 groups
Life StageRDA / AI (mg/day)Upper Limit (mg/day)
Children 1-3 years0.50
Children 4-8 years0.60
Males 9-13 years0.90
Females 9-13 years0.90
Males 14-18 years1.3
Females 14-18 years1.0
Males 19-30 years1.3
Females 19-30 years1.1
Males 31-50 years
Females 31-50 years
Males 51-70 years
Females 51-70 years
Males 70+ years
Females 70+ years
Pregnancy1.4
Lactation1.6

Top Foods Highest in Riboflavin (B2)

Amount per 100g serving. Values in mg per 100g.

Foods Highest in Riboflavin (B2) (Table)

#FoodPer 100gGroup
1Yeast extract spread17.5 mgVegetables and Vegetable Products
2Cereals ready-to-eat, RALSTON Enriched Wheat Bran flakes7.3 mgBreakfast Cereals
3Beverages, fruit-flavored drink, powder, with high vitamin C6.8 mgBeverages
4Beverages, Orange-flavor drink, breakfast type, low calorie,6.8 mgBeverages
5Lamb, New Zealand, imported, liver, cooked, soaked and fried5.3 mgLamb, Veal, and Game Products
6Lamb, variety meats and by-products, liver, cooked, pan-frie4.6 mgLamb, Veal, and Game Products
7Babyfood, cereal, high protein, with apple and orange, dry4.3 mgBaby Foods
8Lamb, New Zealand, imported, liver, raw4.2 mgLamb, Veal, and Game Products
9Moose, liver, braised (Alaska Native)4.1 mgAmerican Indian/Alaska Native Foods
10Lamb, variety meats and by-products, liver, cooked, braised4.0 mgLamb, Veal, and Game Products
11Leavening agents, yeast, baker's, active dry4.0 mgBaked Products
12Formulated bar, MARS SNACKFOOD US, SNICKERS MARATHON Honey N3.8 mgSnacks
13Babyfood, cereal, rice, with bananas, dry3.8 mgBaby Foods
14Egg, white, dried, stabilized, glucose reduced3.7 mgDairy and Egg Products
15Lamb, variety meats and by-products, liver, raw3.6 mgLamb, Veal, and Game Products
16Beverages, Orange drink, breakfast type, with juice and pulp3.6 mgBeverages
17Babyfood, cereal, mixed, with bananas, dry3.6 mgBaby Foods
18Beef, variety meats and by-products, liver, cooked, braised3.4 mgBeef Products
19Beef, variety meats and by-products, liver, cooked, pan-frie3.4 mgBeef Products
20Formulated bar, MARS SNACKFOOD US, SNICKERS MARATHON Energy 3.3 mgSnacks

Health Effects of Riboflavin (B2)

Function

Riboflavin (B2) is a precursor to FMN and FAD coenzymes involved in energy metabolism, cellular respiration, and metabolism of fats, drugs, and steroids. It also supports antioxidant defense via glutathione reductase.

Deficiency Signs

Riboflavin deficiency (ariboflavinosis) causes cracked lips (cheilosis), sore throat, swollen tongue (glossitis), and anemia. Often occurs alongside other B vitamin deficiencies.

Excess / Toxicity

No adverse effects from high intake; excess is excreted in urine (causing bright yellow color). No UL established.

Absorption & Interactions

How It’s Absorbed

Absorbed in the proximal small intestine via specific riboflavin transporters (RFVT1-3). Absorption is saturable, limiting intake to about 27mg per dose. Food-bound FAD/FMN are hydrolyzed first.

Key Interactions
Iron Enhancer
Riboflavin deficiency impairs iron absorption and mobilization; correcting B2 status improves iron utilization
Niacin (B3) Enhancer
FAD (from riboflavin) is required for the enzyme that converts tryptophan to niacin

Estimated Riboflavin (B2) Adequacy by Country

Estimated from national food supply composition (FAO food balance sheets). Shows food supply availability relative to Estimated Average Requirement (EAR), not actual intake. Does not account for fortification, supplements, or distribution inequality.

180 countries7 below 50% EAR109 above 100% EARAvg: 115% EAR
% of EAR from food supply:0-25%25-50%50-75%75-100%100-150%>150%

Frequently Asked Questions

How much Riboflavin (B2) do I need per day?

Adult males need 1.3 mg/day and adult females need 1.1 mg/day.

Which food has the most Riboflavin (B2)?

The food highest in Riboflavin (B2) is Yeast extract spread with 17.5 mg per 100g.

What does Riboflavin (B2) do in the body?

B vitamin (B2) needed for energy production, cell function, and metabolism of fats and drugs.