The B complex vitamins are required for carbohydrate metabolism and production of cellular energy. Blood sugar imbalance results in energy dips and affects physical and mental performance. Without sufficient glucose, muscular and brain function will be impaired.
Government set RDAs (Recommended Daily Amounts) for B vitamins are based on levels required to prevent severe deficiency symptoms. They do not take into account the demands placed on the body by exercise which increases energy turnover vitamin requirements.
Blood testing for B vitamins (apart from B12 and folate which even then is not part of a routine blood screen) is not widely available on the NHS. Blood levels are not a thoroughly reliable indicator of deficiency anyway, since they do not reflect tissue levels in the brain and nervous system. Clinical signs and symptoms, taking into lifestyle factors that increase demand for B vitamins, are a acceptable means of assessing deficiency.
B vitamins are required for a variety of physical and mental functions. B6 is required for synthesis of GABA, a calming neurotransmitter and also for formation of other neuro-transmitters, seratonin, dopamine and adrenalin. Seratonin is involved in mood and healthy sleep patterns. Vitamin B6 is also essential for enzymatic breakdown of glycogen stores for fuel. Protein loading will increase the need for B6.
B12 has a very important relationship to mental health. Impaired memory, concentration and learning ability result from deficiency. Inadequate B12 leads to iron deficiency even when iron is being supplemented and this will adversely affect energy levels and performance. B12 is found predominantly in animal food sources therefore vegetarians and vegans may be vulnerable to lack of this vitamin.
Folic Acid works closely with vitamin B12 and is essential to brain function. It is highly concentrated in spinal fluid and deficiency has been proven to cause neural tube defect in the unborn baby, leading to spina bifida. Folic acid contributes to normal immune function and the average diet is vulnerable to folate deficiency due both to insufficient intake and the fragility of folic acid in storage and food processing.
Due to their water soluble nature, B vitamins need replacing regularly in the body, due to urinary excretion. In addition to the demands of exercise, tea, coffee, alcohol and excess dietary intake of refined carbohydrates and sugar deplete B vitamins as does stress.Vitamin B1 Thiamin deficiency is linked with poor memory and concentration, nervousness, depression and mental confusion.
Vitamin B3 (niacin) deficiency causes pellagra, known as the disease of the “3 Ds”, dermatitis, diarrhoea and dementia. In a study, B3 supplementation improved memory between 10-40% across a mixed age group
Vitamin B2 contributes to the reduction of fatigue and cellular protection against oxidative stress. Research showed the need for Vitamin B2 (riboflavin) was increased in healthy women doing moderate exercise.
In another study, athletes on a healthy diet were found to be deficient in vitamin B2.