Vitamin B6 is the generic name for six compounds with vitamin B6 activity: pyridoxine, an alcohol; pyridoxal, an aldehyde; and pyridoxamine, which contains an amino group; and their respective five-phosphate esters. Pyridoxal 5′ phosphate (PLP) and pyridoxamine five-phosphate (PMP) are the active co-enzyme forms of vitamin B6.
The main function of vitamin B6 is: it helps the body to make many neurotransmitters, which transmit signals from one nerve to another. It is also required for normal brain development and function, and helps the body make the hormones serotonin and nor epinephrine, which influence mood, and melatonin, which helps regulate the body clock. It controls the levels of homo-cysteine in the blood, where homo-cysteine is an amino acid that is associated with heart disease. It even absorbs vitamin B12 and responsible for making red blood cells and cells of the immune system.
According to the national institute of sciences in the United States, has set Tolerable Upper Intake Level (UL) for vitamin B6 is 100 to 200 milligrams per day for adults and older. If people takes more than 500 mg/day or more than 1000 mg/day for longer periods of time, they faced a neurological disorders.
The symptoms include pain, numbness in the extremities or loss of feeling in the legs and imbalance, difficulty in walking, sensitivity to sunlight, nausea, abdominal pain, and loss of appetite. People who take Vitamin B6 late at night have vivid dreams.
However there are rare conditions that people who takes less than 200 mg per day faced a neurological problems which can damage nerves and can cause a sensory neuropathy. If this is the condition, it can be controlled by stopping the supplementation of Vitamin B6. These effects are more if you are taken vitamin B6 in the form of supplements when compared to food sources.