Functions

Vitamin B2 (riboflavin) facilitates energy production as part of the coenzymes FAD and FMN. It is essential for growth, healthy eyes, tissue respiration. It prevents fissures caused by deficiency, eye irritation, and photophobia, and is required for proper blood formation.

Uses

Cataract prevention, rheumatoid arthritis treatment, sickle cell anemia, migraine, carpal tunnel, skin disorders.

Deficiency

Vitamin B2 deficiency symptoms:

• Tissue inflammation/breakdown
• Delayed wound healing
• Characteristic cracks at corners of mouth-cleilosis
• Tongue becomes red swollen -glossitis
• Eyes burn, itch, tear
• Scaly, greasy skin-seborrheic dermatitis in skin folds
• Aversion to bright light
• Depression

Antagonists

Vitamin B2 is light sensitive - destroyed by ultraviolent rays and fluorescent light. It will be leached into cooking water, although it is stable when heated. Alkalis such as baking soda destroy riboflavin.

Excess riboflavin is excreted, so levels must be continually topped up from the diet. Malabsorption disorders may contribute to deficiency.

Diabetes, cancer and cardiac disease may make a riboflavin deficiency worse.

Co-factors

Needs gastric acid for absorption, although it is easily absorbed when this is present. Must be activated in the liver.

Drug Interactions

Sulfa drugs, anti-malarial drugs, estrogen, cathartic agents and alcohol may interfere with riboflavin metabolism. High doses of riboflavin can reduce the effectiveness of the anticancer drug methotrexate. Some antibiotics and phenothiazine drugs may increase riboflavin excretion.

Dose

RDA: 1.3 mg men, 1.1 mg women, pregnancy 1.4 mg, lactation 1.6 mg

Therapeutic dose ranges from: 100 mg to 6 g)

Toxicity

Riboflavin is not well absorbed in high dose so toxicity is unlikely. Some possible toxic effects include itching, numbness, burning sensations and sensitivity to sunlight.

Sources

• Enriched cereals
• Milk & Dairy foods
• Organ meats
• Breads
• Eggs
• Green leafy vegetables