Early mornings, work, errands, children or parents to look after: you reach the evening with your battery almost at zero, especially during transitional months like autumn, when the body readjusts after summer. Among the nutrients involved in how the body gets energy from food are the B vitamins: eight different substances that work together like a team to help your body convert what you eat into energy.
Below we look at what they are, what they are used for, where to find them, who needs them most, and how to choose a supplement, with the support of the scientific literature cited at the end of the article. And if the transition to autumn is taking its toll on you, our article on the post-holiday blues may also be useful.
What are B vitamins?
B vitamins are eight essential and water-soluble micronutrients (B1, B2, B3, B5, B6, B7, B9 and B12) that the body does not produce in sufficient quantities and must therefore obtain from food. They act as coenzymes, i.e., molecules that help the reactions by which the body gets energy from food.
The collective name comes from a laboratory story. At the beginning of the twentieth century, researchers thought they had isolated a single substance, "vitamin B," and only over time did they realize that several were hidden within that fraction, with chemical structures that were even far apart from each other[1].
What keeps them united under the same letter are some common traits: they dissolve in water, mostly work as coenzymes, and are often found in the same foods, from whole grains to legumes, from eggs to fish.
Water-soluble vitamins: why a constant supply is needed
Vitamins are divided into two families. The fat-soluble ones (A, D, E and K) dissolve in fats and the body stores them in adipose tissue and the liver. The water-soluble ones, i.e., vitamin C and all the B vitamins, dissolve in water: they are used when needed and what is left over is largely eliminated with urine[1].
For most B vitamins, the body keeps only small stores, with the partial exception of B12, which the liver can accumulate[1]. For this reason, regularity counts: a varied diet that brings them to your table every day is worth more than an extremely rich meal every now and then. You can also do your part in the kitchen, because folate and thiamine easily pass into the cooking water and suffer from prolonged heat: short cooking times or steaming help preserve more of them[1].
A complex of eight vitamins that work as a team
To understand how B vitamins work, an image can help you. Imagine the chemical reactions that occur in your cells as a long series of steps, each entrusted to an enzyme. Many enzymes, on their own, remain still: they need a helper that attaches to them and activates them. Those helpers are called coenzymes, and B vitamins are among the most in demand of all[1].
Once absorbed, each B vitamin is converted into its active form:
● thiamine becomes thiamine pyrophosphate,
● riboflavin becomes FAD and FMN,
● niacin becomes NAD,
● pantothenic acid becomes part of coenzyme A[1].
These are acronyms you may remember from biology books, and that you find at almost every stage by which the body gets energy from carbohydrates, fats, and proteins.
It is called the "B complex" because B vitamins hardly ever work alone. Riboflavin is needed to activate vitamin B6; B6, in turn, participates in the production of niacin from tryptophan, an amino acid present in proteins; folate and B12 are linked by such close collaboration that one, without the other, remains partly unused[2].
Why are B4, B8, B10 and B11 missing from the numbering?
After B3, it goes to B5, after B7 to B9, then directly to B12. No printing error: in the first half of the twentieth century, every substance that seemed essential for the growth of laboratory animals received a new number, and with more accurate analyses, several candidates dropped out of the list[1].
Adenine (B4) and the compounds called B8 turned out to be molecules that the body produces on its own, para-aminobenzoic acid (B10) is not a vitamin for humans, and B11 turned out to be one of the forms of folate. That is why today the official B vitamins are eight.
What are the 8 B vitamins and what are they used for?
We now come to the heart of the guide. For each vitamin you will find the chemical name, the functions attributed to it, and the main food sources, based on the CREA food composition tables.
Vitamin B1 (thiamine)
Thiamine was the first vitamin of the group to be identified, and its name already tells something about its structure: it contains a sulfur atom, theion in Greek. In its active form, it works in some key steps by which cells get energy from carbohydrates[1].
Vitamin B1 contributes to normal energy metabolism, normal nervous system function, normal psychological function, and normal heart function.
The most generous sources are whole grains, legumes, pork, and nuts, especially walnuts, hazelnuts, and pistachios. Thiamine is sensitive to heat and cooking water: a dish of whole wheat pasta and chickpeas, with some of the legume liquid incorporated into the sauce, retains a greater amount.
Vitamin B2 (riboflavin)
If you had to choose the most versatile B vitamin, riboflavin would be a good candidate. It contributes to normal energy metabolism, the maintenance of normal skin and mucous membranes, the maintenance of normal visual capacity, the maintenance of normal red blood cells, normal iron metabolism, the protection of cells from oxidative stress, and the reduction of tiredness and fatigue.
The name comes from ribose, the sugar that is part of the molecule, and from flavus, "yellow" in Latin. The yellow-orange color is so intense that riboflavin is also used as a food coloring (on the label you will find it with the code E101), and it is the same reason why, after taking a supplement containing it, urine can turn bright yellow. A harmless phenomenon, which we also discuss in the FAQs.
At the table you will find it in milk, yogurt and cheeses, eggs, meat, fish and almonds.
Vitamin B3 (niacin)
Under the name of niacin are gathered two forms: nicotinic acid and nicotinamide, the latter being used more often in supplements. In the body it becomes NAD and NADP, two coenzymes involved in hundreds of reactions, including those that extract energy from food[1]. It has a particularity that distinguishes it from the others: the body can get part of it from tryptophan, with the help of B2 and B6.
Niacin contributes to normal energy metabolism, normal nervous system function, normal psychological function, the maintenance of normal skin and mucous membranes and the reduction of tiredness and fatigue.
You will find it in meat (chicken and turkey in particular), in fish such as tuna and anchovies, in legumes and in cereals.
Vitamin B5 (pantothenic acid)
Here the name says almost everything. Pantothen, in Greek, means "from everywhere", "everywhere": pantothenic acid is so widespread in foods, of both animal and plant origin, that in a varied diet an insufficient supply is quite rare[1]. In the body it enters the structure of coenzyme A, a molecule that acts as a hub between the metabolism of carbohydrates, fats, and proteins.
Pantothenic acid contributes to normal energy metabolism, normal mental performance, the normal synthesis and normal metabolism of steroid hormones, vitamin D and some neurotransmitters, and the reduction of tiredness and fatigue. You will find it in meat, eggs, whole grains, legumes, mushrooms and avocado.
Vitamin B6 (pyridoxine)
Under the name of vitamin B6 are indicated several compounds (pyridoxine, pyridoxal and pyridoxamine) that the body converts into the active form, pyridoxal-5-phosphate. It is one of the most "busy" vitamins of the group: it participates in over a hundred enzymatic reactions, most of which concern amino acids, the building blocks of proteins[1].
It contributes to normal protein and glycogen metabolism (the sugar reserve stored in muscles and the liver), normal energy metabolism, normal homocysteine metabolism, normal cysteine synthesis, normal nervous system function, normal psychological function, normal red blood cell formation, normal immune system function, the regulation of hormonal activity, and the reduction of tiredness and fatigue.
The sources are varied: meat, fish, legumes, nuts, and among plant foods, potatoes and bananas.
Vitamin B7 (biotin)
Biotin is known for its link with beauty, and the reason is due to its contribution to the maintenance of normal hair, normal skin, and normal mucous membranes. In the history of research it was also called vitamin H, from the German Haar und Haut, "hair and skin".
Its work goes beyond the external appearance. Biotin contributes to normal energy metabolism, normal macronutrient metabolism (carbohydrates, fats, and proteins), normal nervous system function, and normal psychological function.
The main sources are egg yolk, nuts, and legumes. A curiosity: raw egg white contains a protein, avidin, which binds biotin and hinders its absorption, while with cooking avidin loses this ability[1].
Vitamin B9 (folate and folic acid)
Folate and folic acid are often used as synonyms, but they indicate two different forms of the same vitamin. Folate is the natural form present in foods, and owes its name to the Latin folium, "leaf", because it was first isolated from spinach leaves[1]. Folic acid is the synthetic, more stable form, used in supplements and fortified foods, which the body in turn transforms into the active forms.
Folate contributes to the growth of maternal tissues during pregnancy, normal amino acid synthesis, normal hematopoiesis (the production of blood cells), normal homocysteine metabolism, normal psychological function, normal immune system function, and the reduction of tiredness and fatigue, and intervenes in the cell division process.
You will find it in leafy green vegetables (spinach, Swiss chard, arugula, turnip tops), legumes, citrus fruits, asparagus, and cabbage. However, it is one of the most delicate vitamins: light, heat, and prolonged storage reduce its content, so it is best to prefer fresh vegetables and short cooking times.
Vitamin B12 (cobalamin)
Cobalamin is the most particular vitamin of the group, for several reasons. It is the most complex from a chemical point of view, with a cobalt atom at the center of the molecule, from which the name comes. It is the only one that the body can accumulate in significant quantities in the liver. And it is found almost exclusively in foods of animal origin[1].
To be absorbed it follows a complex path, which involves the stomach and a protein called intrinsic factor, produced by the cells of the gastric wall. We will come back to it when we see how absorption changes with age.
Vitamin B12 contributes to normal energy metabolism, the normal functioning of the nervous system, normal homocysteine metabolism, normal psychological function, normal red blood cell formation, normal immune system function, and the reduction of tiredness and fatigue, and plays a role in the cell division process.
Among the richest sources are clams and mussels, liver, oily fish such as mackerel and sardines, eggs, and cheeses.
Why are B vitamins important for energy?
After having introduced them one by one, let's look at the big picture. The functions of B vitamins are intertwined in energy metabolism and the renewal of blood cells and defenses[2].
From food to energy: the role in energy metabolism
Think of your cells as small factories and mitochondria as their production department, where an assembly line breaks down sugars, fats, and proteins to extract ATP, the body's energy currency. B vitamins are the skilled workers on that assembly line: thiamine brings sugar derivatives into the mitochondrion, pantothenic acid (as coenzyme A) transports carbon fragments from one station to another, riboflavin and niacin collect the electrons needed to produce ATP, while biotin and B6 work on the metabolism of fats, amino acids, and proteins[1],[2].
One clarification, to clear up a common misunderstanding: B vitamins do not "give energy" like a plate of pasta, because they do not contain calories. They help the body extract it from the food you already eat.
If you want to learn more, read our article on factors that influence energy levels.
Red blood cells, immune defenses, and cell division
Some B vitamins work on the cells that the body continuously renews.
B6 contributes to the normal formation of red blood cells and the normal function of the immune system; folate contributes to normal hematopoiesis, normal immune system function, and the cell division process; B12 contributes to normal red blood cell formation, normal immune system function, and the cell division process.
Folate and B12 form a true pair: to build the DNA of a new cell, folate is needed in its active form, and to unlock one of the forms in which it circulates in the blood, an enzyme that depends on B12 does the job[1],[2].
If you want to understand where vitamins fit into a broader picture of daily habits, read our in-depth article on immune defenses.
What benefits do B vitamins bring to everyday life?
Here is how the recognized functions of B vitamins connect to everyday life.
The most sought-after concern regards tiredness: riboflavin (B2), niacin (B3), pantothenic acid (B5), vitamin B6, folate (B9), and vitamin B12 contribute to the reduction of tiredness and fatigue. It remains that no nutrient takes the place of rest, and that the busiest periods, such as seasonal changes, are tackled first of all with sleep, diet, and movement (you can find some practical ideas in our tips to increase energy levels).
Riboflavin, niacin, and biotin (B7) then contribute to the maintenance of normal skin and mucous membranes, and biotin also to the maintenance of normal hair. On the mental front, pantothenic acid contributes to normal mental performance, while thiamine (B1), niacin, vitamin B6, biotin, folate, and vitamin B12 contribute to normal psychological function: support for the proper functioning of the body when intake is adequate, without promises of results.
Two functions deserve a special mention: vitamin B6 contributes to the regulation of hormonal activity, and folate contributes to the growth of maternal tissues during pregnancy, a period in which any possible supplementation should be agreed upon with the doctor or gynecologist (to learn more, read our article on pregnancy).
Where are B vitamins found in food?
The good news is that a varied diet brings all B vitamins to the table. If you searched Google for “B vitamins foods”, you would have found lists divided vitamin by vitamin: here we think instead in terms of food categories, which are more practical to use in everyday shopping.
● Whole grains, legumes, and nuts: they provide thiamine (B1), niacin (B3), vitamin B6, biotin (B7), and folate. Refining removes the germ and bran, where B vitamins are concentrated[1], so it is best to prefer whole wheat bread, whole wheat pasta and rice, and traditional dishes like pasta and beans or pasta and chickpeas.
● Meat, fish, eggs, and dairy: they are the main sources of riboflavin (B2) and vitamin B12, which is absent in plant-based foods. Oily fish, eggs, yogurt, and cheeses are among the simplest choices, while pork also provides thiamine.
● Leafy greens and other plant sources: spinach, Swiss chard, arugula, and turnip tops are the preferred source of folate, along with asparagus, cabbage, and citrus fruits, while potatoes and bananas contribute to B6 intake. Folate does not like long cooking times: alternate raw, steamed, or quickly sautéed vegetables.
The reference model remains the Mediterranean diet, which with its balance of grains, legumes, vegetables, fish, and a moderate amount of animal products naturally covers a large part of the B vitamin requirements, and is similar to the diet of the Blue Zone, the areas of the world studied for the longevity of their inhabitants.
Who needs B vitamins the most and what signs to watch for?
With a varied diet, most people cover their B vitamin requirements, but in some stages of life and with certain dietary styles, the demands increase or the intake risks being reduced:
● Women of childbearing age, pregnant, and breastfeeding: the requirement for some B vitamins increases, in particular folate, which according to the LARN goes from 330 micrograms per day for adults to 600 in pregnancy and 500 in breastfeeding.
● Those who follow a vegetarian or vegan diet: among the B vitamins, the one to keep an eye on is B12, which is found almost exclusively in foods of animal origin (the others are well represented in whole grains, legumes, nuts, and vegetables). The position paper of the Italian Society of Human Nutrition (SINU) on vegetarian diets indicates that vegans must cover their requirement with fortified foods or supplements[3]; even those who follow a vegetarian diet do well to check their intake with their doctor or nutritionist.
● Over 50s: with age, the stomach tends to produce less acid and, in some people, less intrinsic factor, so part of the B12 present in food is absorbed with more difficulty[1]. It is worth talking to your doctor about (you can find other insights in the section aging healthily).
● Those who live intense periods or follow restrictive diets: hectic pace and little varied meals reduce intake, and even restrictive regimens or habitual alcohol consumption can affect the intake and use of some B vitamins[1]. If you exercise regularly, the starting point remains a diet adequate for your activity level (here you can find some tips to improve sports performance. If you follow continuous pharmacological therapy, ask your doctor for a personalized assessment.
As for the signs, the body can send some clues consistent with the functions of these vitamins:
● tiredness and fatigue even on less busy days
● skin and mucous membranes less in shapethan usual;
● more fragile hair;
● a drop in concentration, in relation to mental performance and psychological function.
Some evidence seems to suggest that even non-optimal intakes, far from a real deficiency, can be accompanied by a lower sense of energy[2]. However, none of the manifestations indicates a deficiency on its own: they can depend on sleep, stress, and many other factors, and only a doctor, also with targeted blood tests, can assess your vitamin status.
Improve Energia: the eight B vitamins in a single formula
If after reading the guide you are considering a supplement that brings together the entire B complex, Improve Energia by Esserre was born from this logic. The formula contains all eight B vitamins together with vitamin C and PunicaPLUS®, Esserre's exclusive Mediterranean pomegranate extract. It is part of the Improve line and theImmunity and Energy area.
The eight B vitamins of Improve Energia and their contribution
The B vitamins in Improve Energia are the same ones you encountered in the previous sheets: thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), vitamin B6, biotin (B7), folic acid (B9) and vitamin B12. In the formula, their contribution is divided into three areas.
● Tiredness and fatigue: pantothenic acid, folate, niacin, vitamin B2, vitamin B6 and vitamin B12 contribute to the reduction of tiredness and fatigue.
● Energy metabolism: pantothenic acid, biotin, niacin, vitamin B1, vitamin B2, vitamin B6 and vitamin B12 contribute to normal energy metabolism.
● Immune system: folate, vitamin B6 and vitamin B12 contribute to the normal function of the immune system.
Vitamin C and PunicaPLUS® pomegranate
Vitamin C and pomegranate are also present in the formula. Vitamin C contributes to the normal function of the immune system, normal energy metabolism, the reduction of tiredness and fatigue and the protection of cells from oxidative stress.
PunicaPLUS® is a dry extract obtained from the whole fruit of the Mediterranean pomegranate (Punica granatum L.). It is derived from pomegranate juice processing waste, which is recovered and transformed into an extract, and contains several bioactive compounds, including polyphenols, punicalagin and ellagic acid[4]. Pomegranate contributes to the antioxidant action.
For the method of use, follow the directions on the label.
Warnings. Food supplements should not be considered a substitute for a varied and balanced diet and a healthy lifestyle. The food supplement cannot in any way replace pharmacological therapy. Do not exceed the recommended daily dose. Keep out of reach of children under 3 years of age. Due to the presence of plant ingredients, different batches may have slightly different colours, without affecting the quality of the finished product. During pregnancy, breastfeeding or if you are undergoing any treatment, consult your doctor or the relevant specialist.
Frequently Asked Questions (FAQ)
Can B vitamins be taken every day?
Yes, daily intake is within the normal method of use for B vitamin supplements, provided that the daily dose indicated on the label is respected without exceeding it. As they are water-soluble vitamins, regularity of intake is what matters. During pregnancy, if you take medication or have specific doubts, consult your doctor first.
Is it better to take B vitamins in the morning or in the evening?
The reference is always the method of use stated on the label, and there is no time of day to which different effects can be attributed. The most useful advice is to choose the time that is easiest for you to remember, for example by linking it to a fixed habit such as breakfast: for water-soluble vitamins, consistency matters more than the time.
Why does urine become bright yellow?
It is a known and harmless effect, due to riboflavin (vitamin B2). The portion of riboflavin that the body does not use is eliminated with urine and, thanks to its intense yellow colour, colours it bright yellow. Many B vitamin supplements report this among the warnings on the label.
What is the difference between folate and folic acid?
Folate is the natural form of vitamin B9, present in leafy green vegetables, legumes and citrus fruits. Folic acid is the synthetic, more stable form, used in supplements and fortified foods, which the body converts into active forms. You can find all the details in the section dedicated to vitamin B9.
Do vegans need to supplement vitamin B12?
According to the position paper of the Italian Society of Human Nutrition (SINU) on vegetarian diets, those who follow a vegan diet must cover their vitamin B12 requirements with fortified foods or supplements, because the vitamin is found almost exclusively in products of animal origin[3]. The most suitable methods should be agreed upon with a doctor or nutritionist.
Scientific references
- Combs GF Jr, McClung JP. The Vitamins: Fundamental Aspects in Nutrition and Health. 5th ed. London: Academic Press, Elsevier; 2017.
- Tardy AL, Pouteau E, Marquez D, Yilmaz C, Scholey A. Nutrients. 2020;12(1):228.
- Agnoli C, et al. Nutrition, Metabolism and Cardiovascular Diseases. 2017;27(12):1037-1052.
- Esposito C, et al. Processes. 2022;10(2):208. DOI: 10.3390/pr10020208. Study conducted by the Department of Pharmacy of the University of Naples Federico II in collaboration with the R&D department of Esserre Pharma.
Regulatory and institutional references
The functions reported for the vitamins correspond to the health indications authorized by the Regulation (EU) 432/2012. The antioxidant effect reported for pomegranate (Punica granatum, fruit) corresponds to those provided by the ministerial guidelines on the physiological effects of substances and plant preparations, referring to the list of permitted plants as per the DM 10 August 2018. Reference intake levels: SINU, LARN – Reference Intake Levels of Nutrients and Energy for the Italian Population. Vitamin content in foods: CREA, Food and Nutrition Research Center, Food Composition Tables.
