pyridoxine
A water-soluble vitamin obtained from meat, poultry, and eggs. It acts as a co-enzyme to over 60 enzymes and plays a vital role in protein metabolism. Those on high protein diets may require more vitamin B6. The vitamin is essential for efficient nerve and muscle function. It is also involved in the initial breakdown of glycogen, and in the formation of antibodies and haemoglobin. Deficiency, although relatively rare, causes nervous irritability, anaemia, convulsions in infants, and sores around the eyes and mouth in adults. Excessive intake results in depressed tendon reflexes and loss of sensation in the fingers and toes. Intakes greater than 500 mg per day are associated with permanent sensory nerve damage. In the UK, the adult Reference Nutrient Intake is 1.4 mg per day for males, and 1.2 mg per day for females.
