Functions	Dosage	Toxicity	Further Information	What you need to eat
The vitamin is required for 60 enzymatic reactions. It is involved in chemical transmission between nerve cells, especially in the brain. It plays a part in energy and red cell production. Supplements can be useful to alleviate infant seizures and premenstrual tension.	The RDA is between 1.6 and 2.2 mg per day, with the higher levels recommended during pregnancy.	Toxicity only occurs in high doses and causes severe nerve damage. Skin problems insomnia and muscle weakness may also occur.	It may relieve symptoms of menopause and infertility. Chronic supplementation with high doses may be habit forming and induce sleepiness and well as tingling in the extremities.	Animal products including offal, fish and eggs. Vegetable sources include melon, cabbage, bananas and avocados.