Surprising Health Benefits of B Vitamins

One of the vital functions of B vitamins is to help us turn food into energy. However, as recent research shows, eating a range of foods rich in B vitamins can have substantial benefits, throughout our life, from the cradle to a healthy old age.

Way back in 1970 the first study to conclusively confirm the link between folate (vitamin B9) deficiency and neural-tube defects such as spina bifida was published. This led to the now widespread practice of folic acid supplementation before and during pregnancy. However, emerging research points to lesser-known benefits of some of the other B vitamins during pregnancy.


One such vitamin is vitamin B3, known as niacin, and found in fish, beans, nuts and mushrooms. An Australian study on mice found that a higher intake of B3 may reduce the incidence of miscarriages and birth defects in specific cases. The research followed observations of major birth defects in human babies with a specific genetic mutation that affects the body’s ability to make a molecule called nicotinamide adenine dinucleotide (NAD). The team’s subsequent studies on mice discovered that added B3 in the diet during gestation prevented the malformations in offspring. However, more human studies would be needed.

In the UK, scientists at the University of Southampton have also studied the impact of vitamin B3 during pregnancy, and found that women with a higher blood level of a particular type of B3 called nicotinamide (one of the components of NAD), were less likely to have babies with eczema than those with lower levels.

While more research is needed to determine the safe dosage and any possible side effects of B3 during pregnancy, current advice remains to eat foods rich in B vitamins and to take multivitamins specially formulated for pregnancy.

The importance of a good balance of B vitamins was also highlighted by a study published in the journal Clinical Nutrition, which found that pregnant women with high levels of folate but low levels of vitamin B12 were significantly more likely to develop gestational diabetes. The study mostly observed this nutrient imbalance in vegetarian women, particularly of Asian descent. (Vitamin B12 is found in foods such as meat and fish. Vegetarian sources include fermented foods such as kefir, kimchi and Marmite, and some types of mushroom.)

Anti-aging and Mental Health

A 2016 paper describes vitamin B12 deficiency as a “missed opportunity to prevent dementia and stroke”; and research certainly shows a strong link between a good intake of B vitamins and the prevention of dementia and mental deterioration as we age. For example, a study from France evaluated the diets of around 1,300 people and found that lower intake of folate was associated with a higher risk of dementia. In the UK, a study sponsored by the Food Standards Agency (FSA) and carried out over four years found that low vitamin B6 was linked to a 3.5 times higher risk of accelerated cognitive decline, and on February 2017 a review of studies by the University of Manchester found that high doses of B vitamins significantly reduced symptoms of schizophrenia.

So why are B vitamins linked so strongly with anti-aging and mental health? Some of the answers can be found from a major clinical trial undertaken at Oxford University in 2010, and findings on homocysteine — an amino acid derived from protein-rich foods such as meat, fish and eggs. Although homocysteine plays an important role in many metabolic functions, high levels are associated with cardiovascular disease and increased risk of dementia or Alzheimer’s disease.

However, a good dietary supply of B vitamins, particularly B6, folate and B12, as found in foods such as almonds, eggs, whole grains, green leafy vegetables, lean meat, fish and dairy products, can keep homocysteine in check. Data from the Oxford University study show that B vitamin supplementation for two years improved mental performance in people with high levels of homocysteine, and also that supplementation reduced brain shrinkage in areas particularly affected by Alzheimer’s disease by 30 percent.

Interestingly, there appears to be an added advantage to eating good fats with your B vitamins. Two studies found that the action of B vitamins to improve the mental health in the elderly was much more dramatic when the participants had good levels of omega-3 fats in their bloodstream. This is a good reason to combine those oily fish, nuts and seeds with whole grains and leafy vegetables. (For an exemplar serving suggestion: think of salmon, brown rice and spinach! Or a vegetable stir fry with nuts on brown rice!)

Lung disease

One area of research where the picture is less clear is that relating to lung health.

Many people may have taken fright at recent headlines claiming that vitamin B supplements increased the risk of lung cancer in men. However, what those headlines did not mention was that the risk was specifically found in male smokers.

The story related to the findings of a study published in August 2017, which analyzed data from a 10-year study of around 78,000 people. The analysis found that male smokers taking 20 milligrams (mg) of vitamin B6 per day for 10 years were three times more likely to go on to develop lung cancer, while male smokers taking 55 micrograms (mcg) of vitamin B12 per day for 10 years were around four times more likely to develop the disease.

It should be noted that the study found that only smokers were affected and that they were taking high doses of B vitamins: for adult men, the NHS recommends 1.4 mg of vitamin B6 and 1.5 mcg of B12.

Further research is underway to find out why the B vitamins may have this effect, and there is no evidence that a diet rich in B vitamin foods has the same impact.

There is also some evidence to show that B vitamins protect the lungs against pollution, in particular, a type of pollution known as particulate matter, which comprises tiny particles that can enter the bloodstream via the lungs, and cause damage to DNA, leading to inflammation. One Canadian study found that a combination of folate, vitamin B6 and vitamin B12 protected the lungs by preventing the particles from causing damage to DNA.

If you are concerned about your own vitamin levels, tests for deficiencies (e.g. vitamin B12) can be carried out via a GP or nutritional therapist. It is always recommended to seek professional advice as not all individuals will need to supplement above the dietary intake.

1. Shi H et al (2017). NAD deficiency, congenital malformations, and niacin supplementation. New England J of Med, 377(6), 544-552.
2. El-Heis S et al (2016). Higher maternal serum concentrations of nicotinamide and related metabolites in late pregnancy are associated with a lower risk of offspring atopic eczema at age 12 months. Clin & Exp Allergy, DOI: 10.1111/ cea.12782
3. Lai JS et al (2017). High folate and low vitamin B12 status during pregnancy is associated with gestational diabetes mellitus. Clin Nutr.