Why you need it
Vitamin B6 is needed by over 100 enzymes, most of which are involved in protein metabolism. It helps make serotonin, dopamine, and hemoglobin, and supports your immune system.
Too little and too much
A shortage shows up as skin and lip inflammation, anemia, and irritability. It's more common in people who drink too much alcohol or have kidney disease.
You can't get too much from food, but taking high doses in supplements for months may cause numbness and tingling in your hands and feet.