Riboflavin (vitamin B2) deficiency symptoms
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Riboflavin (Vitamin B2) Deficiency Symptoms: Neurological, Hematological, and Systemic Effects
Neurological Symptoms of Riboflavin Deficiency
Riboflavin deficiency, especially due to genetic transporter defects, can cause a range of neurological symptoms. These include muscle weakness, cranial nerve deficits such as hearing loss, sensory symptoms like sensory ataxia, feeding difficulties, and respiratory problems. These symptoms are linked to sensorimotor axonal neuropathy and cranial neuropathy, and can be severe if not treated promptly with riboflavin supplementation, which is often lifesaving 12.
Hematological and Metabolic Manifestations
Riboflavin plays a crucial role in red blood cell production and iron metabolism. Deficiency can interfere with iron handling, leading to anemia, particularly when iron intake is also low. This is because riboflavin enhances iron absorption and mobilization from stores. Even in the absence of obvious clinical symptoms, biochemical riboflavin deficiency can contribute to anemia, especially among women and children 45.
Effects on Other Vitamins and Metabolic Pathways
Riboflavin is essential for the metabolism of other B vitamins, including vitamin B6, niacin, and folate. Deficiency can disrupt the folate cycle, increase homocysteine levels (a risk factor for cardiovascular disease), and impair the activation of other vitamins, leading to broader metabolic disturbances. This can result in tissue damage, particularly affecting the epithelial, reproductive, and nervous systems .
Reproductive and Developmental Symptoms
In animal studies, riboflavin deficiency has been shown to cause reproductive problems such as premature birth, stillbirths, weak offspring, and high neonatal mortality. These findings highlight the importance of riboflavin for reproductive health and development, and suggest that similar risks may exist in humans, especially during pregnancy 37.
Risk Groups and Dietary Considerations
Riboflavin deficiency is more common in populations with low intake of animal-derived foods, such as vegetarians and vegans, as well as in the elderly and adolescents. Plant-based diets generally provide less riboflavin, and while gut microbiota may help produce some riboflavin, this is often not enough to meet the body's needs 46.
Conclusion
Riboflavin deficiency can present with a wide range of symptoms, from neurological and hematological issues to reproductive and metabolic disturbances. Early recognition and supplementation are critical, as treatment with riboflavin is safe and effective in reversing symptoms and preventing serious complications. Populations at higher risk, such as those with restricted diets or genetic transporter defects, should be monitored closely for signs of deficiency.
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