Vitamin B2 (synonyms: riboflavin, lactoflavin) is a vital dietary component of the vitamin B complex. If this is not supplied to the body, deficiency symptoms (hypo-/avitaminosis) occur.
Vitamin B2 is absorbed in the human body in the small intestine. Two active forms, flavin mononuclotide and flavin adenine dinucleotide, are found in the human body. Vitamin B2 is water soluble and alkali and light sensitive. It cannot be stored and absorption beyond requirement is not possible.
It is found mainly in milk, eggs, meat and fish, as well as in cereals and mushrooms.
The main function of vitamin B2 is as a coenzyme in carbohydrate metabolism as well as in other metabolic processes.
The following symptoms, among others, may occur with a vitamin B2 deficiency:
- Anemia, normochromic and normocytic (anemia).
- Ariboflavinosis syndrome – symptom complex of inflammatory skin lesions, cheilosis, oral rhagades, and visual and neurovegetative disturbances.
- Ocular changes: Lens opacity, keratitis (corneal inflammation).
- Cheilosis (lip cracking)
- Inflammatory skin lesions
- Oral rhagades
- Pruritus (itching)
- Seborrheic dermatitis – skin inflammation associated with increased sebum production.
- Stomatitis – inflammation of the mouth
The procedure
Material needed
- EDTA blood
Preparation of the patient
- Not necessary
Disruptive factors
- The blood sample must be stored in the dark
Standard values
| Value in μg/dl | |
| Normal range | 6-12 |
Indications
- Suspected vitamin B2 deficiency in the context of a general vitamin deficiency (B2 hypovitaminosis alone does not occur)
Interpretation
Interpretation of increased values
- Not known
Interpretation of lowered values
- Alimentary (nutritional)
- Severe malnutrition and malnutrition
- High cigarette consumption
- Chronic alcohol abuse
- Long-term parenteral nutrition
- Malabsorption (malfunction of absorption)
- Chronic enteritis
- Crohn’s disease
- Celiac disease (gluten-induced enteropathy) – chronic disease of the mucosa of the small intestine (small intestinal mucosa), which is based on hypersensitivity to the grain protein gluten.
- Diseases
- Diabetes mellitus due to losses via urine
- Chronic dialysis
- Medication
- Barbiturates, chlorpromazine, hormonal contraceptives – in particular, riboflavin requirements increase due to interactions with various drugs (e.g., certain antidepressants)
- Increased need
- Young women
- Age ≥ 65 years
- Pregnant and breastfeeding women
- Underweight (BMI < 18.5)
- Heavy physical activity
- Severe diseases
- After surgery and trauma
Other notes
- The normal requirement for vitamin B2 is 1.2 mg/d for women and 1.4 mg/d for men.
Attention. Note on the state of supply (National Nutrition Survey II 2008) 20% of men and 26% of women do not reach the recommended daily intake.