Normal range: Up to 15%: adequate, 15-25%: borderline; > 25%: deficiency
Comment: Vitamin B6 a water soluble vitamin, acts as coenzyme (pyridoxal – 5 phosphate) in protein, carbohydrate and lipid metabolism, as well as in heme synthesis. Decreased: chelitis, dermatitis, glossitis. A cause of neonatal convlusion
Sample: 3 mL EDTA plasma, send immediately, protected from light, freeze