Vitamin B2, or riboflavin, is a vital water-soluble vitamin that helps convert food into energy, supports cellular function, and maintains healthy skin, nerves, and eyes by assisting in the metabolism of fats, proteins, and carbs, with deficiency causing cracked lips, sore tongue, and light sensitivity, while common sources include milk, eggs, lean meats, and leafy greens, and supplements can treat deficiencies or manage migraines.  
Benefits & Functions

    Energy Production: Converts food (carbs, fats, proteins) into glucose for energy. 

Antioxidant: Protects cells from damage and supports immune function. 
Cell Growth: Essential for skin, digestive tract lining, blood cells, and brain function. 
Metabolism: Helps convert other B vitamins (B6, folate) into usable forms. 

Deficiency Symptoms (Ariboflavinosis)

    Cracks and sores at the corners of the mouth (cheilosis).
    Swollen, magenta-colored tongue (glossitis).
    Skin issues, especially around the nose and scrotum.
    Eye fatigue, burning, and sensitivity to light. 

Rich Food Sources

    Dairy: Milk, cheese, yogurt.
    Meats & Eggs: Lean meats, liver, kidneys, eggs.
    Vegetables: Green leafy vegetables, fortified cereals.
    Other: Nuts, fish, enriched grains. 

Therapeutic Uses (Prescribed)
Treating severe deficiencies, Preventing migraine headaches (often at higher doses), and Managing corneal thinning (keratoconus). 
Side Effects & Considerations

    Excess riboflavin is generally excreted in urine, giving it a bright yellow/orange color. 

High doses in supplements are usually well-tolerated but may cause mild stomach upset.