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Vitamin B2

Vitamins Biomarker

Sample Needed

Collection Type: Blood

Body System

Related System: Vitamins

Overview

Vitamin B2 (riboflavin) is a water‑soluble vitamin essential for energy production, redox reactions and the metabolism of fats, drugs and other vitamins (B6, folate). The test measures riboflavin status indirectly (erythrocyte glutathione reductase activation coefficient, EGRAC) or directly (plasma/serum or RBC riboflavin). Testing is considered when signs of deficiency appear—glossitis, cheilosis, angular stomatitis, seborrheic dermatitis, anemia, or unexplained fatigue—and in people with malabsorption, alcoholism, or long‑term drug use that affects B‑vitamin metabolism. Requirements vary: needs rise in pregnancy/lactation; older adults, strict vegetarians, and those with chronic illness are at higher risk of low levels.

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Test Preparation

No special preparation is required

Why Do I Need This Test

Profile: included in vitamin/nutritional deficiency panels.
Symptoms prompting test: mouth/tongue inflammation, cracked lips, skin rashes, unexplained fatigue or anemia.
Diagnoses/monitoring: detects riboflavin deficiency (ariboflavinosis) and monitors repletion therapy.
Causes of abnormal levels: poor intake, malabsorption, chronic alcohol use, some drugs (eg, isoniazid), or rare transporter defects.
Biological meaning: low values indicate impaired flavoprotein function and disrupted energy/redox metabolism; high values usually reflect recent supplementation.
Family history: hereditary transporter/metabolic disorders or familial riboflavin‑responsive neurologic syndromes.

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Understanding Test Results

EGRAC ≤1.2 indicates adequate riboflavin status.
EGRAC 1.2–1.4 suggests marginal/early deficiency and warrants dietary review or repeat testing.
EGRAC >1.4 indicates biochemical deficiency and risk for clinical signs (glossitis, cheilosis, dermatitis, microcytic or normocytic anemia) and should prompt supplementation and investigation of causes (malabsorption, alcohol use, interacting drugs).
Plasma riboflavin <3 µg/L supports deficiency; values within 3–15 µg/L generally reflect adequate status; markedly elevated plasma riboflavin (>15 µg/L) usually reflects recent high intake or supplementation rather than toxicity (true toxicity is rare).
Follow up abnormal results with clinical correlation, dietary assessment and, if needed, treatment and re‑testing.

Normal Range

EGRAC 0.8–1.2 (unitless) OR Plasma/serum riboflavin 3–15 µg/L (≈11–56 nmol/L)

FAQs

Q: What is vitamin B2 deficiency?

A: Vitamin B2 (riboflavin) deficiency causes sore throat, cracks at mouth corners (cheilosis/angular stomatitis), red swollen tongue (glossitis), seborrheic dermatitis, eye sensitivity to light and sometimes anemia. It arises from poor dietary intake, alcoholism, malabsorption or some medications. Diagnosis uses clinical signs and lab tests; treatment is dietary improvement and riboflavin supplementation, with most people improving quickly.

Q: Which foods have vitamin B2?

A: Vitamin B2 (riboflavin) is found in dairy (milk, yogurt, cheese), eggs, liver and other meats, poultry, and oily fish (salmon). Plant sources include almonds, mushrooms, spinach, broccoli, and legumes (lentils, soybeans). Fortified breakfast cereals and whole grains also provide riboflavin. Including a mix of these foods helps maintain adequate B2 intake.

Q: What are the benefits of taking B2?

A: Riboflavin (vitamin B2) supports energy production by helping convert carbohydrates, fats and proteins into usable fuel, and aids red blood cell formation and iron metabolism. It helps maintain healthy skin, eyes and mucous membranes, supports nervous system function, and participates in antioxidant defenses (glutathione recycling). Adequate B2 may also reduce migraine frequency in some individuals.

Q: What is the difference between B2 and B12?

A: Vitamin B2 (riboflavin) is a water‑soluble vitamin needed for energy production, cellular metabolism and antioxidant defenses; common sources are dairy, eggs, green vegetables and grains. Vitamin B12 (cobalamin) supports nerve function, red blood cell production and DNA synthesis; it’s mainly in animal foods and requires intrinsic factor to absorb. B2 deficiency causes mouth and skin symptoms, B12 deficiency causes anemia and neurological problems.

Q: How can I increase my B2 vitamin?

A: Increase riboflavin by eating more dairy (milk, yogurt, cheese), eggs, lean meats, fish, green leafy vegetables, nuts, legumes, and fortified cereals/whole grains. Consider a B‑complex or riboflavin supplement if dietary intake is low, after checking with your healthcare provider. Address absorption issues or medication interactions with medical advice and have levels checked if deficiency is suspected.

Q: What are the symptoms of low B2?

A: Low vitamin B2 (riboflavin) commonly causes sore throat, swollen or red tongue, cracks at the mouth corners (angular cheilosis), dry scaly skin or seborrheic dermatitis, and eye problems such as light sensitivity or watery eyes. Fatigue, weakness and mouth or lip inflammation are frequent; prolonged deficiency can contribute to anemia and neurological symptoms. See a healthcare provider for testing and treatment.