B Vitamins, B12 & Folate: A Pharmacist’s Guide to What You Need to Know
By Lauren O’Reilly, Pharmacist
B vitamins are often grouped together on supplement shelves, but they don't all do the same thing. They are a family of eight different vitamins, each with its own role in the body.
B vitamins are involved in processes including energy metabolism, nervous system function, red blood cell formation and normal cell function. Most people can get the B vitamins they need from a varied, balanced diet, but there are some important exceptions - particularly vitamin B12 and folic acid (which is also a B-vitamin) before and during pregnancy.
B vitamins have different jobs
B vitamin |
What it helps with |
Food sources |
B1 – Thiamine |
Releasing energy from food and nervous system function |
Wholegrains, nuts, peas, fortified cereals |
B2 – Riboflavin |
Energy metabolism, skin, eyes and nervous system |
Milk, eggs, yoghurt, fortified cereals |
B3 – Niacin |
Energy metabolism, skin and nervous system |
Meat, fish, eggs, wheat flour |
B5 – Pantothenic acid |
Releasing energy from food |
Meat, eggs, mushrooms, avocado, wholegrains |
B6 |
Protein metabolism and formation of haemoglobin |
Poultry, fish, oats, bananas, nuts |
B7 – Biotin |
Helps the body make fatty acids |
Eggs, nuts and other foods |
B9 – Folate |
Red blood cell formation and normal cell division |
Green vegetables, peas, beans, fortified cereals |
B12 |
Red blood cells, nervous system function and energy metabolism |
Meat, fish, dairy, eggs, fortified foods |
The HSE notes that most people should be able to get the majority of these vitamins through a varied and balanced diet.
One important point: B vitamins don't provide an energy boost simply because they're B vitamins. They are involved in the body's normal energy-yielding processes, but taking extra B12, for example, won't improve energy or endurance if you already have enough.
Vitamin B12 is particularly important for the nervous system and blood cells
Vitamin B12 helps the body make red blood cells, maintain a healthy nervous system, release energy from food and use folate. Adults aged 19 - 64 need around 1.5 micrograms of B12 per day according to HSE guidance.
B12 is naturally found mainly in animal-derived foods, including meat, fish, milk, cheese and eggs. Some fortified breakfast cereals and plant-based foods also contain added B12.
This is why people following a vegan diet, or have dietary restrictions which mean they consume less of the foods listed above, need to pay particular attention to their B12 intake.
Who is more likely to develop B12 deficiency?
Diet isn't the only consideration. B12 deficiency can also occur because the body isn't absorbing enough of the vitamin.
Higher-risk groups can include people who:
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Follow a vegan diet without reliable B12 supplementation or fortified foods
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Have pernicious anaemia. Pernicious anaemia is an important cause of B12 deficiency. It is an autoimmune condition in which the immune system attacks cells in the stomach that produce intrinsic factor, a protein needed to absorb vitamin B12. Without enough intrinsic factor, the body cannot absorb B12 properly from food. This means someone with pernicious anaemia may need lifelong B12 treatment, often initially through injections, rather than simply increasing B12-rich foods.*
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Have coeliac disease or other conditions affecting absorption*
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Have had certain gastrointestinal surgery
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Take certain medicines that can affect B12 absorption, including metformin or proton pump inhibitors such as omeprazole
B12 deficiency also becomes more common with age.
B12 deficiency and its associated causes need to be diagnosed by a medical professional, and should not be self-diagnosed or treated.
Low B12 can cause much more than tiredness
B12 deficiency can develop gradually, so symptoms aren't always immediately obvious.
Possible symptoms include:
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Extreme tiredness or lack of energy
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Pins and needles or numbness
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Muscle weakness
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A sore or red tongue
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Mouth ulcers
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Disturbed vision
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Problems with memory, understanding or judgement
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Depression or confusion
Importantly, some neurological symptoms can occur without anaemia. These symptoms can also be indicative of other conditions, so it is very important to investigate any symptoms you have that are concerning you with a medical professional.
If you're concerned that you may have B12 deficiency, don't simply assume you need a high-dose supplement. A GP can investigate the cause with appropriate blood tests, and treatment depends on why the deficiency has occurred (if indeed one is present). Some people need tablets, while others may need B12 injections. If B12 has been recommended to you – check the dose required with your healthcare provider. The Better You B12 Oral Spray is a convenient dosage format if it is required, and provides 1200 micrograms daily per 4 sprays.
B12 and B-complex aren't the same thing
This is one of the distinctions I think gets lost when looking at supplements.
A B12 supplement provides vitamin B12 specifically. A B-complex usually combines several of the B vitamins in one product.
If you're considering… |
What it means |
B12 |
A targeted source of vitamin B12 |
B-complex |
A combination of several B vitamins, which work synergistically together |
Folic acid |
The supplemental form of folate (vitamin B9) |
A multivitamin |
May contain several B vitamins alongside other vitamins and minerals |
A B-complex isn't automatically “better” because it contains more nutrients. The right choice depends on what you're actually trying to address, and where relevant, what you have been prescribed. If a B-complex is required, or desired, and there is no suspected serious deficiencies, the AYA B-Complex is a well-balanced B-complex formulation.
Folate and folic acid are closely related, but not identical
Folate is vitamin B9, the naturally occurring form found in foods. Folic acid is the form used in supplements and some fortified foods.
Folate is needed for the formation of healthy red blood cells and is particularly important during pregnancy because adequate folic acid helps reduce the risk of neural tube defects such as spina bifida.
Good dietary sources include leafy green vegetables, broccoli, Brussels sprouts, peas, chickpeas and kidney beans, as well as some fortified breakfast cereals.
Folic acid is one supplement I would not leave until pregnancy is confirmed
If there is a possibility that you could become pregnant, the HSE recommends taking 400 micrograms of folic acid every day, such as the Active Iron Active Folic L-Methylfolate 400mcg, which is a once-daily folate supplement containing 400mcg of folate from Quatrefolic® L-Methylfolate, a biologically active form of folate designed for better absorption compared with standard folic acid. Check the folic acid content of your pregnancy supplement before adding a separate folic acid supplement. Products such as Pregnacare Original, Pregnacare Max and Active Iron Prenatal already provide 400 µg folate/folic acid per daily dose. If you have been prescribed a higher dose of folic acid by your GP, follow that advice rather than changing your dose yourself.
Ideally, start at least 3 months before becoming pregnant and continue through the first 12 weeks of pregnancy. The HSE advises taking it even if you aren't actively planning a pregnancy, because the baby's neural tube develops very early - often before someone knows they're pregnant, and approximately 50% of all pregnancies are unplanned.
Some women are advised to take a higher 5 mg dose, including those at increased risk of neural tube defects. This is a prescribed dose and should be discussed with your GP rather than self-started.
It's still important to eat folate-rich foods, but the HSE specifically advises that dietary sources alone are not enough to provide the recommended amount of folic acid needed around pregnancy.
Can you take a B-complex every day?
For most people, there's no need to take a B-complex simply because B vitamins are “good for energy.” If your diet is varied and you don't have an increased requirement or deficiency, supplementation may not provide additional benefit.
And although many B vitamins are water-soluble, that doesn't mean unlimited amounts are harmless.
Vitamin B6 is particularly worth watching. Higher intakes can cause peripheral neuropathy, including loss of sensation in the hands and feet, and prolonged high-dose use can sometimes cause lasting damage. Do not exceed the recommended dosage on the pack if buying over the counter supplements or follow the dose prescribed by your doctor where relevant.
Folic acid also deserves care at higher doses. Taking more than 1 mg per day can mask symptoms of B12 deficiency, potentially allowing neurological damage to progress. Never exceed recommended daily dosage on the pack without medical advice and / or medical investigation into the suspected deficiency.
My pharmacist's approach to B-vitamin supplements
I wouldn't recommend a B-complex automatically to anyone who feels tired.
I'd first consider why someone is tired and whether there are symptoms or circumstances suggesting a deficiency. B12 is particularly worth considering if someone has a restricted diet, absorption issues or relevant medication use.
If you're taking several supplements, check the labels too. It's surprisingly easy to take overlapping products - for example, a multivitamin, B-complex and separate B12 - without realising how much you're getting altogether.
And if you have symptoms suggesting B12 or folate deficiency, testing and finding the cause is more useful than guessing which supplement to buy.
The bottom line
B vitamins are a family rather than a single nutrient, and each has a different role. Most people can get enough through a balanced diet, but B12 deserves particular attention in people at risk of deficiency, while folic acid is essential for anyone who could become pregnant.
A B-complex isn't automatically better than a targeted supplement, and higher doses aren't automatically more effective.
My advice as a pharmacist is to supplement with a purpose: know what you're taking, check the dose, and investigate persistent symptoms rather than assuming you simply need more vitamins.