Vitamin B6 (pyridoxine)
Pyridoxine is needed for protein and carbohydrate metabolism, the formation of red blood cells and certain brain chemicals. It influences brain processes and development, immune function and steroid hormone activity.
- Sources of pyridoxine – include cereal grains and legumes, green and leafy vegetables, fish and shellfish, meat and poultry, nuts, liver and fruit.
- Excessive intake – can lead to harmful levels in the body that can damage nerves. Symptoms include walking difficulties and numbness in the hands and feet. Large doses of B6 taken over a long period can lead to irreversible nerve damage.
- Premenstrual syndrome (PMS) and carpal tunnel syndrome – there is some evidence that vitamin B6 may be useful in the treatment of carpal tunnel syndrome and PMS. Seek advice from a doctor before using large doses of this supplement (above 100 mg per day) because of the danger of overdose and nerve damage.
- Pyridoxine deficiency – people who drink excessive alcohol, women (especially those on the contraceptive pill), the elderly and people with thyroid disease are at particular risk of deficiency. Symptoms include insomnia, depression, anaemia, smooth tongue and cracked corners of the mouth, irritability, muscle twitching, convulsions, confusion and dermatitis.