Isolated vitamin B6 deficiency is uncommon in the US and usually occurs alongside low levels of other B vitamins. It is more likely with kidney disease, malabsorption conditions, alcohol dependence or certain medications. Deficiency is associated with microcytic anemia, dermatitis, depression and confusion, and weakened immune function; in infants it can cause seizures.
Common symptoms
Microcytic anemia (small red blood cells)
Dermatitis with scaling on the lips and cracks at the corners of the mouth
Swollen tongue (glossitis)
Depression and confusion
Weakened immune function
In infants: irritability, abnormally acute hearing and seizures
Symptoms often overlap with other B-vitamin deficiencies
At-risk groups
People with kidney disease, including those on dialysis or after a kidney transplant
People with rheumatoid arthritis
People with malabsorption conditions such as celiac disease, Crohn's disease or ulcerative colitis
People with alcohol dependence
Long-term users of some antiepileptic drugs
People with rare genetic disorders such as homocystinuria
When to see a doctorSee a doctor about persistent skin problems around the mouth, unexplained microcytic anemia when iron levels are normal, or numbness and tingling. Long-term high-dose B6 can itself cause nerve damage, so do not exceed the upper limit without medical supervision.