B vitamins are a family of water-soluble vitamins, similar in molecular structure, yet chemically distinct they are largely recognized for their contribution to metabolism whilst having their own unique activities. In a complementary manner B vitamins are mostly grouped rather than found singularly in foods.

The physiological roles of B vitamins lie in enzymatic reactions, major examples are energy production, hormone production, methylation, nervous system function and psychological function.

Furthermore an individual may supplement with B vitamins when their diet cannot supply the necessary amount to support an area of weakness or a condition, such as; cognition, energy, detoxification, cellular repair and replacement, cardiovascular health, nerve health and stress. B6, B12 and folate (B9) support homocysteine recycling, however it is suggested that reducing elevated homocysteine in the brain contributes to improved cognitive performance3. It is suggested that replenishing low levels of B5 in periods of stress improve the individual’s ability to cope. However, for B6 this is not proven in clinical trials, yet B6 is incremental in the conversion of L-dopa to dopamine, furthermore it was shown that generating a B6 deficiency in experimental studies reduced serotonin, thus suggesting that the normal metabolism of the neurotransmitters dopamine and serotonin may improve an individual’s ability to cope with stress.

Similarly low levels of B6, B12 and folate were shown to correlate with high homocysteine, however studies that investigated the replenishment of such vitamins showed improved cardiovascular markers besides reduced homocysteine values.25 Furthermore, the recycling of homocysteine to produce methionine and subsequently S- adenosyl methionine; the methyl donor is involved in different genetic regulatory mechanisms that include those in brain development.3 Neurological health such as numbness of the skin, hands or feet, muscle weakness and impaired motor coordination are indicative of B12 deficiency induced degeneration of myelin of the spinal cord.

The National Diet and Nutrition Surveys concluded that the UK population achieves a basic B vitamin intake, but the quantities are likely to be inadequate. Thus B vitamin deficiency is rare, yet more could be done to achieve optimal dietary intakes of these nutrients.

What is Pantothenic Acid, B5 good for?

Pantothenic acid, discovered in the 1930s derives its name from the Greek word panthos meaning ‘from everywhere’, as it is widely spread throughout foods. Although highly prevalent in foods, B5 is fragile, easily denatured by processing, for example; heating, refining, canning or freezing, subsequently B5 consumption could be greatly impaired for those eating a highly processed diet. Further considerations for a reduced B5 intake; those using the oral contraceptive pill or antibiotics.

B5 is known to contribute to the production of CoA a cofactor for fatty acid energy production and as an acyl carrier protein to facilitate fatty acid synthesis and lysine synthesis. It is thought that these functions are the basis for the role B5 has in energy production, adrenal support and hormone production.

Dermatitis and impaired fat and carbohydrate metabolism. Megaloblastic anaemia.

Deficiency related conditions

B Vitamins and Stress.

STRESS- can be defined as psychological, physiological or environmental pressures that elude the ability to cope. Stress is a tightly regulated process that involves hormone signalling and a negative feedback loop to regain homeostasis. It is known that a number of B vitamins are involved within the stress response and further investigations have questioned the role of nutrient deficiency on stress levels. A meta-analysis evaluated 8 studies that investigated the influence of B vitamin supplementation on stress, mood and mild psychiatric symptoms. It was reported that supplementation significantly reduced the levels of perceived stress, the psychiatric symptoms and anxiety. The authors concluded that micronutrient supplementation has a beneficial effect on stress where those with high doses of B vitamins may be effective in improving mood.

B vitamins and mood.

MOOD- the normal production and receptor binding of neurotransmitters are necessary in the psychological response to the environment. Subsequently, imbalances of these compounds can contribute to changes in mood and feelings of wellbeing. Maintaining a balanced psychological function involves the utilisation of B vitamins in the synthesis of neurotransmitters alongside proteins, lipids and hormones.

A randomised, placebo-controlled, double–blind, parallel group trial assessed the cognitive and mood effects of a high dose B-complex vitamin with vitamin C over 33 days on males aged 30-55 years in full time employment. The authors reported significant improvements in the perceived stress scale scores, in addition they reported less mental fatigue before and after a cognitive demand test. The same cohort were later assessed for cognitive performance and psychological state. The vitamin and mineral group reported greater ‘physical stamina’ throughout and greater ‘concentration’ and ‘mental stamina’ during the work day and from day 14 onwards they reported greater subjective ‘alertness’ during the work day. The authors then went on to explore multivitamin and mineral supplementation over a greater time period of 9 weeks on females aged 25-50 years to assess cognitive function and task related mood. The vitamin and mineral group showed a resilience and improvement on the negative mood effects of an extended task.19 Finally the authors investigated the cognitive and mood response of children to multivitamin and mineral supplementation. The children aged 8-14 years underwent supplementation and laboratory cognitive and mood assessment for 12 weeks. The vitamin and mineral group showed greater accuracy on attention tasks.20 All the results led the authors to conclude that healthy members of the population may benefit from augmented levels of supplementary vitamins and minerals.

To establish the effect of multivitamin and mineral supplementation on a group of young adults, a four week multivitamin and mineral intervention on 18-40 year olds found the subject group had significantly reduced homocysteine levels, significantly increased blood B vitamin levels and significantly improved mood scores.

B Vitamins for Energy

ENERGY - fatigue and lack of energy is a trait of mitochondrial disease or dysfunction, which subsequently is a feature of chronic fatigue syndrome (CFS).22 The suggested causal mechanisms include DNA and reactive oxygen species damage to the mitochondria thus impairing activity. A unique study assessed women of reproducible age with diagnose chronic fatigue syndrome for 2 months whilst treated with a multivitamin and mineral formula. It was reported that the vitamin and mineral group saw a significant improvement in super oxidase dismutase activity levels besides significant decreases in fatigue, sleep disorders, autonomic nervous system symptoms, headaches and subjective feeling of infection. Subsequently the authors concluded that treatment with multivitamin and mineral supplements could be a safe and easy intervention to improve symptoms and quality of life in CFS patients.23

B Vitamins and Mental function

COGNITION- cognitive function is the cerebral functions that lead to knowledge, that encompassing the mechanisms of acquiring information, reasoning, memory, attention and language. Cognitive decline has been shown to be associated to stress and conditions such as dementia and Alzheimer’s disease. Studies have confirmed that elevated homocysteine is a powerful modifiable biomarker associated with cognitive decline.

A study explored the effect of B vitamin supplementation on the rate of brain atrophy in those with mild cognitive impairment reported that the treatment group showed a slower rate of brain atrophy than the placebo group. Furthermore the authors reported that cognitive performance was related to brain atrophy rates in this population

The HAPIEE (Health, Alcohol and Psychosocial factors in Eastern Europe) study aimed to explore the association between serum folate and vitamin B12 concentrations with cognitive function in those aged 45-69 years. The 2 year study reported positive significant associations between folate and B12 intake and cognitive activity scores. This highlights the requirement of lifelong adequate nutrition in terms of preserving cognitive function. 

Furthermore, a review argues that B vitamins are one of the priority preventative treatments that is potentially a cost effective treatment for cognitive health. The authors suggest that in the UK B vitamin administration could delay the onset of dementia and reduce the cost of healthcare.

B Vitamins and Homocysteine levels.

HOMOCYSTEINE - homocysteine levels can be influenced by B vitamin status due to their role in homocysteine recycling. A series of research was triggered by the homocysteine theory of cardiovascular disease that was extended to Alzheimer’s disease. It suggested that homocysteine could cause cognitive impairment via neurotoxicity. This questioned; would a decrease in the recycling of homocysteine to methionine compromise cognitive function? Subsequently would homocysteine reducing strategies reduce cognitive impairment? A tremendous amount of research has explored daily B vitamin treatments concluding that B6, B12 and folate are beneficial.

The association between homocystinuria (elevated homocysteine levels) and the increased risk of cardiovascular events was demonstrated in the 1960s30, since then further investigation has been undertaken to explore risk reduction via B vitamin treatment. A random control trial investigated the treatment with folic acid or placebo on a population with one pre-existing cardiovascular risk marker. It was reported that after 18 months treatment the folic acid subject group saw significantly reduced homocysteine levels and a significant regression of the biomarker ‘carotid intima-media thickness’; an atherosclerotic marker.

A review discussed the potential cardiovascular health risks in relation to homocysteine levels in children and adolescents based on the results of 15 studies. Three of the studies found correlations between homocysteine values and a family history of cardiovascular disease. Additionally it was concluded that an increase in homocysteine was observed in males and proportionate to age.

An interesting study evaluated homocysteine levels, B12 and folate in patients with acute aortic dissection and chronic thoracic aortic aneurysms, both potentially fatal conditions. It was reported that patients with acute aortic dissection were associated with high homocysteine and low folate values.

A case-reference observational study investigated the effects of folate, B12 and B6 on plasma homocysteine concentrations and to estimate the risks for coronary artery disease (CVD). An inverse relationship was observed between serum folate and homocysteine, furthermore the mathematical model used to estimate risk showed greater risk for those with elevated homocysteine.

Due to inconsistencies in some trials it has been proposed that those with a genetic predisposition that produces elevated cardiovascular outcomes that these may have positive outcomes that are independent from homocysteine levels.