Pyridoxal is one of the three natural forms of vitamin B₆, along with pyridoxamine and pyridoxine (also called "pyridoxol"). All of these forms are converted in the human body into a single biologically active form, pyridoxal 5-phosphate. All three forms of vitamin B₆ are heterocyclic organic compounds. Green plants are a natural source of pyridoxal, and its deficiency in the human body can lead to serious complications such as epilepsy and seizures.