Biologically Active Vitamin B6 Vitamin B6 presented in its most biologically active form, pyridoxal-5-phosphate. B6 is critical for sustained energy release from the bodyÕs stores, amongst many other important functions. Vitamin B6 is used to synthesise the enzymes involved in the metabolism of protein, fats and carbohydrates. Vitamin B6 is needed in the conversion of the amino acid tryptophan to niacin (B3). Vitamin B6 is used in the support of hormonal balance and proper immune function. Vitamin B6 is involved in the formation of body proteins and structural compounds, red blood cells and prostaglandins.