Vitamin B6 - Information and Sources
Vitamin B6 is a mixture of the water soluble compounds pyridoxal, pyridoxine, pyridoxamine and their phosphates, eg pyridoxal phosphate (PLP). All the compounds can be inter-converted and PLP, the active form, is a cofactor for a large number of metabolic enzymes in protein metabolism.
Requirements of vitamin B6 are related to protein intake. Adults should aim for 15µg per gram protein intake per day. Therefore an average 80g protein per day will require 1.2mg of vitamin B6. Deficiency is very rare but symptoms include convulsions and dizziness. Alcoholics are at risk due to dietary inadequacy and because alcohol promotes the destruction of B6 from the body. Vitamin B6 can be toxic in high amounts causing nerve damage to the arms and legs, but this is only from supplementation. B6 supplements have been used to reduce symptoms of pre-menstrual tension, but caution is advised.
Vitamin B6 is abundant in our diets. Cooking, storage and processing losses of vitamin B6 vary and in some foods may be more than 50%. Plant foods lose the least during processing as they contain mostly pyridoxine which is the more stable form. Milk can lose 30-70% of its vitamin B6 content when dried. Particularly good sources include:
- Wholegrain products
- Fortified breakfast cereals
- Wheat bran
- Red meat
- Beans and lentils
- Soya beans
- Sunflower seeds