Vitamins

Vitamin B2 (Riboflavin) — What Your Blood Test Result Means

ScanHealth Learn Vitamins Vitamin B2 (Riboflavin)

Your Energy Transfer Vitamin

Riboflavin is the backbone of FAD and FMN—two coenzymes that hundreds of metabolic reactions depend on for transferring electrons during energy production. It also helps recycle other antioxidants (like glutathione) and is needed to activate vitamin B6 and convert folate to its active form.

What is Vitamin B2 (Riboflavin)?

Riboflavin is a water-soluble B vitamin that forms FAD and FMN coenzymes, essential for energy production, antioxidant recycling, and metabolism of other B vitamins. It's sensitive to light (milk in glass bottles loses riboflavin quickly).

What High Vitamin B2 (Riboflavin) Means

Excess riboflavin turns your urine bright yellow (harmless). Toxicity is essentially unknown.

Common symptoms:

Bright yellow urine (harmless) · No known toxicity

What Low Vitamin B2 (Riboflavin) Means

Cracked corners of your mouth (angular cheilitis), sore throat, red/swollen tongue, and light sensitivity are classic signs. Riboflavin deficiency rarely occurs alone—it usually comes with other B vitamin deficiencies.

Common symptoms:

Angular cheilitis (cracked mouth corners) · Sore, red tongue (glossitis) · Sore throat · Light sensitivity (photophobia) · Red, itchy eyes · Skin rash · Anemia

Why It Matters

When normal:

Backbone of FAD and FMN coenzymes

Recycles glutathione (master antioxidant)

Activates vitamin B6 and folate

Energy production from fats, carbs, and proteins

Risks if abnormal:

Deficiency: angular cheilitis, glossitis, photophobia, anemia

Often accompanies other B vitamin deficiencies

Migraine prevention potential (high-dose)

What Can Cause Abnormal Levels?

Inadequate Intake

45% likely

Found in dairy, eggs, lean meats, and fortified cereals. Vegans avoiding dairy may be at risk.

Alcohol

35% likely

Alcohol impairs riboflavin absorption and utilization.

Hypothyroidism

Thyroid hormones are needed for riboflavin conversion to active coenzymes.

Eating Disorders

Restricted intake leads to multiple B vitamin deficiencies simultaneously.

What You Can Do

Riboflavin foods: dairy, eggs, almonds, mushrooms, lean meats, fortified cereals

Impact: Dietary sources prevent deficiency \u00B7 Timeline: 2-4 weeks

If lifestyle changes aren't enough:

Riboflavin: 25-100mg daily (or as part of B-complex)

Impact: Replenishes stores, supports other B vitamins \u00B7 Timeline: 2-4 weeks

Riboflavin 400mg daily for migraine prevention

Impact: Studies show ~50% reduction in migraine frequency \u00B7 Timeline: 8-12 weeks

Recommended retest: 3 months

Related Markers

vitamin_b6 folate vitamin_b1 hemoglobin
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice. Always consult your doctor for diagnosis and treatment.

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