- Last Update On : 2013-02-03
Pyridoxal-5- phosphate is the active form of vitamin B6 in the body. It is the vitamer that is measured in serum or plasma to determine vitamin B6 levels. Pyridoxal phosphate is a cofactor for a variety of enzymes including the transaminases.
The primary reason for ordering vitamin B6 is to diagnose pyridoxine deficiency, which has been associated with microcytic hypochromic anemia, dermatitis, neuritis, stomatitis and cheliosis. Chronic B6 deficiency can lead to secondary hyperoxaluria ,increasing the risk of kidney stones. Chronic B6 deficiency has also been associated with nerve compression disorders such as carpal tunnel and tarsal tunnel syndromes, but this relationship is controversial.
Markedly elevated levels of pyridoxal-5-phosphate are observed in hypophosphatasia, a disorder characterized by skeletal deformaties and low alkaline phosphatase levels. High levels are also detected in patients taking megadoses of pyridoxine (>2g per day). Megadose therapy may cause peripheral neuropathy.
Reference range is 5 – 50 ug/L
Specimen requirement is one red top or green top tube of blood.