Causes of Vitamin B2 (Riboflavin) Deficiency
Vitamin B2 deficiency primarily results from inadequate dietary intake, malabsorption disorders, and increased physiological demands, with the body's inability to store riboflavin making consistent daily intake essential. 1
Primary Dietary Causes
Low dietary intake is the most common cause of riboflavin deficiency, particularly when diets lack dairy products, meat, fortified cereals, and dark-green vegetables. 1 The body cannot store riboflavin in ample amounts and it is excreted in urine, making constant dietary supply necessary. 1
Key dietary risk factors include:
- Avoidance of dairy products (the primary riboflavin source in Western diets), particularly in patients with anorexia nervosa 1
- Insufficient consumption of meat, fatty fish, eggs, and dark-green vegetables 1
- Lack of fortified grains, cereals, and bakery products 1
- Poor dietary variety, especially in elderly populations with decreased intake of dairy products 1
Malabsorption Conditions
Gastrointestinal disorders that impair absorption in the proximal small intestine cause riboflavin deficiency, as absorption occurs through an active, carrier-mediated, saturable transport process. 1
High-risk malabsorptive conditions include:
- Short bowel syndrome 1
- Celiac disease 1
- Chronic inflammatory bowel conditions affecting the proximal small intestine 1
Medical Conditions and Physiological States
Multiple chronic diseases and physiological states increase riboflavin requirements or impair its metabolism, creating deficiency even with adequate intake. 1
At-risk conditions include:
- Renal disease (pre-dialysis, hemodialysis, and peritoneal dialysis patients) 1
- Thyroid dysfunction 1
- Diabetes mellitus 1
- Alcoholism (impairs absorption and metabolism) 1
- Pregnancy and lactation (increased requirements: 1.4 mg and 1.6 mg daily respectively) 1
Increased Metabolic Demands
Acute illness and trauma states dramatically increase riboflavin requirements through enhanced metabolic activity and inflammatory responses. 1
High-demand states include:
- Surgery, trauma, burns, or fractures 1
- Inflammatory conditions (plasma riboflavin decreases 30-40% with inflammation) 1
- Active infections 2
- Intense physical exercise 2
Medication-Induced Deficiency
Certain medications interfere with riboflavin absorption, metabolism, or increase its excretion. 1
Implicated medications include:
- Psychotropic drugs 1
- Tricyclic antidepressants 1
- Barbiturates 1
- Proton pump inhibitors (indirectly through altered gut environment) 1
Age-Related Factors
Elderly populations face multiple concurrent risk factors including decreased dairy intake, altered absorption and metabolism, and polypharmacy. 1 Studies show that over 50% of older adults have suboptimal riboflavin status, likely due to decreased intake of dairy products combined with age-related physiological changes. 1
Inadequate Supplementation in Medical Nutrition
Riboflavin deficiency can occur during parenteral nutrition if not provided daily, as demonstrated in a case where administration only 3 times weekly resulted in low plasma levels. 1 The recommended dose in parenteral nutrition is 3.6-5 mg daily. 1
Important Clinical Considerations
Riboflavin deficiency rarely occurs in isolation and is frequently associated with concurrent pyridoxine (B6), folate, and niacin deficiencies. 1 This occurs because riboflavin is required for the metabolism of other B vitamins, particularly through pyridoxine phosphate oxidase and methylene-tetrahydrofolate reductase. 1
Light exposure destroys riboflavin, making storage and handling of riboflavin-containing solutions critical in clinical settings. 1 All flavins are light-sensitive and decompose after irradiation. 1