The B group of vitamins have a critical role in energy metabolism and are involved in many enzyme processes. For example niacin is needed for muscle energy production and folate is needed for the making of new cells such as red blood cells (1 p 188).
Bananas contain the essential B group vitamins thiamin, riboflavin, niacin, pantothenic acid, folate and vitamin B6. The banana is the best fruit source of vitamin B6 (one medium banana provides about 15% of your daily needs) in an easy-to-absorb form (8).
Vitamin B6 is needed for normal amino acid and protein metabolism and is involved in the production of neurotransmitters including serotonin and GABA. About half of the B6 in the body is associated with energy production in the muscles (1 p 190-1).
Vitamin B6 has been of interest to researchers in recent years as its role has become better understood. Population research shows that adequate vitamin B6 consumption is linked to a better chance of conception and pregnancy outcome in women and a lower risk of bowel cancer (7, 10).
Vitamin B6 needs rise after your 50th birthday, as well as during pregnancy and breastfeeding to meet the needs of the baby (9).There has been suspicion that older people may not be getting enough B6 through their diet either through not eating enough or due to a reduced absorption from the intestines. There is increasing evidence that B6 plays an important role in lowering the risk of bowel cancer (10, 11).
One medium banana will provide around 12% of your daily needs of folate (2010 independent analysis), an important B vitamin during pregnancy. Eating enough folate during pregnancy protects the baby from spinal malformations such as spina bifida (9 p 248). The banana provides more folate than any other commonly eaten fruit (12).
A medium banana also offers around 5% of your daily needs of thiamin, niacin, riboflavin and pantothenic acid. The advantage of the banana is that it is soft and easy to peel and eat, so it becomes the ideal fruit for people with arthritis or missing teeth, as well as being perfect when introducing solids to infants.References: