What are the benefits of the B vitamins?

B vitamins B: a big family!

The group of B vitamins comprises 8 water-soluble vitamins, each with its own number: B1, B2, B3, B5, B6, B8, B9 and B12 (1). Though chemically very different, they share certain functional similarities.

Acting as coenzymes of many biological reactions, the B vitamins play a synergistic role in all metabolic and energy pathways (converting nutrients into energy) (2). Some also have a free radical-fighting (antioxidant) effect. They are in fact essential for normal functioning of the body.

As we are unable to produce and/or store B vitamins in the amounts necessary for our needs, any surplus being eliminated via the urinary tract, we need to obtain a regular supply from the diet (3).

B vitamins and their benefits in detail

Vitamin B1 (thiamine)

Absorbed in the jejunum (the middle part of the small intestine), vitamin B1 or thiamine is primarily concentrated in the liver, muscles, kidneys and nervous system (4).

Converted in the liver into its active form, thiamine pyrophosphate, it supports normal energy metabolism by ensuring the conversion of carbohydrates into energy, as well as the breakdown of certain amino acids (valine, leucine, isoleucine) (5).

It also helps to maintain normal nervous system and heart function and psychological function. It’s thought to be involved in, amongst others, the production of acetylcholine, a neurotransmitter integral to memory and learning processes as well as muscle activity (6).

Vitamin B2 (riboflavin)

Also known as riboflavin or lactoflavin, vitamin B2, like thiamine, supports normal nervous system function and energy metabolism, though by affecting macronutrients as a whole (proteins, carbohydrates and fats) (7).

Acting in tandem with vitamins B3 and B6, it is also a component of two redox coenzymes (FMD and FAD), and thus plays a role in protecting cells against oxidative stress(8).

Highly-concentrated in the retina, it helps ensure healthy vision, especially in low light situations (9). It also helps maintain normal skin by contributing to keratin production.

As it is involved in iron metabolism, vitamin B2 also plays a role in maintaining healthy red blood cells, and thus helps reduce fatigue by ensuring good tissue oxygenation (10).

Vitamin B3 (niacin)

Discovered during experiments on nicotine, vitamin B3 used to be known as nicotinic acid before being renamed niacin. It’s also known as vitamin PP (pellagra-preventive), as deficiency in this vitamin can lead to the condition known as pellagra (11).

Like its cousins, vitamin B3 helps maintain normal energy metabolism, with a special affinity for the breakdown of fats. In particular, it acts as a precursor of NAD and NADP, two coenzymes which govern cellular energy production and fat molecule synthesis (12).

Playing a role in healthy nervous system function, it may have a protective effect on neuronal cells (13).

Vitamin B5 (pantothenic acid)

From the Greek pantos (meaning ‘from everywhere’), pantothenic acid, or vitamin B5, is found in almost all living organisms. Once absorbed, it is converted into its biologically active form, coenzyme A (14).

Vitamin B5 supports healthy energy metabolism, with a particular role in breaking down fats. It also supports normal production of steroid hormones, vitamin D and certain neurotransmitters (such as adrenaline) (15).

Its effect on the adrenal glands also explains why it is able to help reduce fatigue (16).

Vitamin B6 (pyridoxine)

Present in food in various forms (pyridoxine, pyridoxal...), vitamin B6 is bioactive in the form of pyridoxal-5-phosphate (PLP) (17).

Involved in the enzymatic conversion of many amino acids, vitamin B6 plays a role, amongst others, in the:

• normal metabolism of glycogen and proteins (18) ;
• normal metabolism of homocysteine and synthesis of cysteine (19) ;
• normal function of the nervous system (through endogenous synthesis of various neurotransmitters: adrenaline, GABA, dopamine…) (20) ;
• normal formation of red blood cells (role in haemoglobin synthesis) (21) ;
• normal function of the immune system (close link with antibody production and release of histamine) (22) ;
• reduction of fatigue (23).

Vitamin B8 (biotin)

Sometimes referred to as vitamin H or coenzyme R, vitamin B8 (biotin) plays a role in the metabolism of all macronutrients by facilitating the mobilisation of fats, the conversion of sugars into glucose, and the synthesis of amino acids (24). Produced by our gut flora, the fact that it is eliminated via urine means we need to ensure an adequate supply from the diet.

Much in demand in the cosmetics field, biotin helps maintain normal hair and skin by promoting cell renewal (25). With an interdependent relationship with vitamins B9 and B12, it also supports good nervous system function (26).

Vitamin B9 (folate)

Vitamin B9 (folic acid or folate) plays a major role in cell division and supports normal synthesis of amino acids(27). It is crucial for pregnant women as it is involved in normal maternal tissue growth during pregnancy. A lack of folate in the pre-conception period significantly raises the risk of neural tube defects in the foetus (28).

It is also involved in forming normal red blood cells by allowing them to mature, as well as in normal immune system function by supporting production of white blood cells (29).

It has also been shown to help maintain normal psychological function and reduce fatigue (30).

Vitamin B12 (cobalamin)

Found only in animal-source products, vitamin B12 is one of the few B vitamins that the body is able to store in significant quantities (primarily in the liver, pancreas, brain and heart) (31).

It has direct role in ensuring good nervous system function as it is a component of the myelin sheaths which surround nerve cells and enable the transmission of nerve signals (32).

In conjunction with vitamin B9, it supports normal formation of red blood cells and helps maintain normal immune system function, as well as being involved in cell division (production of genetic material) (33).

What about the others?

You’ll have noticed that the the numbering of the B vitamins is not sequential. The strange gaps in the nomenclature are because certain substances once thought to be vitamins were later found not to be.

Vitamin B4, which used to correspond to adenine, is now associated with choline. B10 refers topara aminobenzoic acid(PABA), while B11 used to refer to folic acid (B9).

Vitamin B7 is a little different: in some English-speaking countries and in Germany, it remains the term used for biotin (vitamin B8).

Which B vitamin complex should you choose?

If you’d like to supplement with vitamin B, opt for a complex that contains forms offering excellent absorbability and uptake.

The coenzymated versions, already in an active form, should be your first choice: unlike the free forms, they do not need to go through any digestive stages in order to be activated.

For optimal efficacy, however, they need to be taken sublingually in order to bypass the digestive tract and avoid being reconverted into the free form (one such product is Coenzymated B Formula, which combines the 8 active forms of vitamin B in a single, sublingual tablet).