Vitamin B6 (Pyridoxal Phosphate)

Pyridoxine (vitamin B₆) is a complex of six vitamers: pyridoxal, pyridoxol, pyridoxamine (pyridoxine), and their 5′-phosphate esters. Because of its role as a cofactor in a number of enzymatic reactions, pyridoxal phosphate (PLP) has been determined to be the biologically active form of vitamin B₆. Vitamin B₆ is important in heme synthesis and functions as a coenzyme in amino acid metabolism and glycogenolysis. Vitamin B₆ deficiency is associated with symptoms of irritability, weakness, depression, dizziness, peripheral neuropathy, and seizures. In the pediatric population, deficiencies have been characterized by diarrhea, anemia, and seizures.

Vitamin B₆ is ubiquitous. Vitamin B₆ is three related compounds: pyridoxine, occurring mainly in plants; and pyridoxal and pyridoxamine, which are present in animal products. The major dietary sources of vitamin B₆ are meat, poultry, fish, potatoes, and vegetables; dairy products and grains contribute lesser amounts. Readily absorbed from the intestinal tract, vitamin B₆ is excreted in the urine in the form of metabolites. Vitamin B₆ deficiency rarely occurs alone; it is more commonly seen in patients deficient in several B vitamins. Those particularly at risk for deficiency are patients with uremia, liver disease, absorption syndromes, malignancies, or chronic alcoholism. High intake of proteins increases the requirements for vitamin B₆. Deficiency is associated with hyperhomocystinemia. Vitamin B₆ has low toxicity because of its water-soluble nature; however, extremely high doses may cause peripheral neuropathy. The RDA of vitamin B₆ is 1.3–1.7 mg/day for adult males and 1.3–1.5 mg/day for adult females, depending on age.

Lab units Conversion Calculator. Convert Vitamin B6 (Pyridoxal Phosphate) level to nmol/L, µg/L, µg/dL, µg/100mL, µg%, ng/mL. Clinical laboratory units online conversion from conventional or traditional units to Si units. Table of conversion factors for Vitamin B6 (Pyridoxal Phosphate).