The main B vitamins benefits come down to one job done eight different ways: they help your body turn food into usable energy and keep your nerves, brain and blood working normally. Each one has its own speciality: B12 and folate for red blood cells and nerves, B1 for carbohydrate metabolism, B6 for neurotransmitters, and so on. They won't give you energy you don't already have, but running low on any of them can leave you tired, foggy or worse.
Here's what each B vitamin actually does, who's most likely to run short, and where supplement marketing overreaches. Since we put B vitamins in our own THRIVE and IGNITE tablets, we'll also show you exactly how much they contain and how that compares with the upper limits.
Key takeaways
- There are eight B vitamins: B1, B2, B3, B5, B6, B7, B9 and B12. They work as helpers (coenzymes) in energy metabolism and nerve function.
- They don't act as stimulants. Extra B vitamins only improve energy if you were low to begin with.
- B12 and folate are the ones most worth watching: vegetarians, older adults, people on metformin and people planning pregnancy are at higher risk of shortfalls.
- "Water-soluble" doesn't mean harmless. High-dose B6 has been linked to nerve damage, and high-dose niacin to flushing and liver issues.
- Biotin supplements can distort some blood test results. Tell your doctor if you take them.
Why are there so many B vitamins?
Early 20th-century scientists thought "vitamin B" was one substance. It turned out to be a family of chemically different compounds that often appear in the same foods and work together in the same metabolic pathways, so they kept a shared letter and gained numbers. The gaps (B4, B8, B10, B11) belong to substances later found not to be true vitamins.
Asia has a particular history here. Beriberi, a disease of thiamine (B1) deficiency, was widespread in parts of Asia in the 19th and early 20th centuries as machine-polished white rice replaced whole grain. Research by Christiaan Eijkman in Java, which linked the disease to polished rice, contributed to the discovery of vitamins and earned him a share of the 1929 Nobel Prize.
B vitamins benefits: which one does what?
The adult daily amounts below come from the US National Institutes of Health Office of Dietary Supplements (ODS). Malaysia's Recommended Nutrient Intakes are broadly similar.
| Vitamin | Main role | Good food sources | Adult daily need (approx.) |
|---|---|---|---|
| B1 (thiamine) | Turns carbohydrates into energy; nerve function | Wholegrains, legumes, seeds, fortified cereals | 1.1–1.2 mg |
| B2 (riboflavin) | Energy production; metabolism of other B vitamins | Milk, yoghurt, eggs, lean meat, mushrooms | 1.1–1.3 mg |
| B3 (niacin) | Energy metabolism; DNA repair; skin and nerve health | Chicken, fish, peanuts, wholegrains | 14–16 mg NE |
| B5 (pantothenic acid) | Part of coenzyme A, central to fat and carb metabolism | Found in most foods: chicken, eggs, mushrooms, avocado | 5 mg |
| B6 (pyridoxine) | Protein metabolism; making neurotransmitters like serotonin; red blood cells | Chicken, fish, chickpeas, bananas, potatoes | 1.3 mg (higher after 50) |
| B7 (biotin) | Fat, carb and protein metabolism | Cooked eggs, nuts, seeds, salmon | 30 mcg |
| B9 (folate) | Cell division, DNA synthesis, red blood cells; foetal neural tube development | Dark leafy greens, legumes, dhal, fortified grains | 400 mcg DFE (600 in pregnancy) |
| B12 (cobalamin) | Red blood cells, nerve function, DNA synthesis | Meat, fish, eggs, dairy, fortified foods | 2.4 mcg |
Do B vitamins give you energy?
This is the most common misunderstanding, so let's be precise. B vitamins help your cells extract energy from carbohydrates, fats and protein. That's why regulators allow claims like "contributes to normal energy-yielding metabolism".
But they aren't fuel themselves, and they don't work like caffeine. If your levels are already adequate, taking more doesn't produce more energy; the excess of most B vitamins is simply excreted in urine (which explains the bright yellow colour after a B complex, courtesy of riboflavin).
Where B vitamins make a real difference is when you're low. B12 or folate deficiency can cause a type of anaemia with fatigue, breathlessness and poor concentration. If you're constantly tired, it's worth asking your doctor to check B12, folate and iron together. Our guide to iron deficiency as a hidden cause of fatigue covers the related blood tests.
What do B vitamins do for your brain and focus?
Several B vitamins are involved in making neurotransmitters and maintaining the myelin sheath that insulates nerves. B12 deficiency, in particular, can cause memory problems, low mood, numbness and tingling, and if left untreated, lasting nerve damage.
What the evidence doesn't show is that extra B vitamins sharpen focus in well-nourished people. Trials of B vitamin supplements for cognition in healthy adults have produced mostly modest or inconsistent results. The takeaway: preventing deficiency protects your brain; megadosing doesn't upgrade it. We cover what actually helps concentration in brain food: what helps and what's hype.
Who is most at risk of B vitamin deficiency?
- Vegetarians and vegans. B12 comes almost entirely from animal foods and fortified products. Long-term vegetarians, including many in Malaysia's Indian and Buddhist communities, should consider regular B12 checks and a reliable source.
- Adults over 50. Stomach acid declines with age, making it harder to absorb B12 from food. The NIH recommends older adults get most of their B12 from fortified foods or supplements.
- People taking metformin. Long-term use of this common diabetes medicine is linked to lower B12 levels. Given how common type 2 diabetes is in Malaysia, this is worth raising with your doctor.
- People on long-term acid-reducing medicines such as proton pump inhibitors.
- Anyone who may become pregnant. Health authorities, including the WHO, recommend folic acid before conception and in early pregnancy to reduce the risk of neural tube defects.
- Heavy drinkers. Alcohol interferes with thiamine and folate absorption.
Can you take too much of a B vitamin?
Yes, and this surprises people. Three to know:
- B6. Long-term high intake from supplements can cause peripheral neuropathy: numbness, tingling and pain in the hands and feet. The US upper limit is 100 mg a day, and the European Food Safety Authority set a lower limit of 12 mg a day in 2023. Some regulators have reported nerve symptoms at doses found in combination supplements, so check how many products you take contain B6.
- Niacin (B3). Doses above the 35 mg upper limit can cause flushing, and very high doses used under medical supervision have been linked to liver problems.
- Folic acid. The upper limit for adults is 1,000 mcg a day from supplements and fortified foods. High intakes can mask the anaemia of B12 deficiency while nerve damage progresses.
A separate issue: biotin. High-dose biotin, often marketed for hair and nails, can interfere with certain lab tests, including some thyroid and heart (troponin) tests, producing falsely high or low results. The US FDA has warned about this. Stop biotin before blood tests if your doctor advises, and always mention it.
Food first, then fill gaps
A varied diet with wholegrains, legumes, eggs, fish or meat, dairy and plenty of greens covers B vitamins for most people. A simple checklist:
- Swap some white rice for brown or mixed rice for extra B1.
- Eat dhal, chickpeas or tempeh a few times a week for folate and B6.
- Include eggs, fish, chicken or dairy regularly, or a fortified alternative if you're vegetarian.
- Add dark leafy greens like bayam or kailan most days.
If your diet is patchy, a moderate-dose supplement containing B vitamins is an easy way to top up (more on ours below). For how to build a sensible routine without doubling up on nutrients, see how to build a supplement routine that makes sense.
Where TANO fits: the B vitamins in THRIVE and IGNITE
If your diet has gaps (long days, skipped breakfasts, a lot of white rice), TANO THRIVE is our daily base. A 2-tablet serving provides vitamin B6 6 mg, B12 18 mcg, B5 30 mg and B3 40 mg, alongside 20 mg iron, 800 mg vitamin C, 16 mg zinc and a 1.6 g greens blend. B6, B12 and iron contribute to normal energy-yielding metabolism and the reduction of tiredness and fatigue. TANO IGNITE, our apple cider vinegar tablet, adds a smaller B6 1.9 mg and B12 2.2 mcg per serving.
Honest numbers, given the upper limits above: THRIVE plus IGNITE together give 7.9 mg B6, under the EFSA limit of 12 mg, so don't add a separate high-dose B6 or B complex on top. THRIVE's 40 mg B3 is above the 35 mg US limit, which was set to avoid flushing from the nicotinic acid form; if you flush easily or take other niacin products, ask a pharmacist. THRIVE's label lists no added folic acid, so anyone planning pregnancy still needs folic acid.
Take 2 tablets in 250–500 ml cold water once daily. Check with your doctor if you're pregnant, on metformin or other medication. Neither replaces a varied diet or a B12 blood test.
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This article is general information, not medical advice. Talk to a doctor or pharmacist before starting supplements, especially if you are pregnant, taking medication such as metformin or managing a health condition.
Frequently asked questions
What are the main benefits of B vitamins?
B vitamins help your body convert food into energy and support normal nerve function, brain function and red blood cell production. Folate is particularly important before and during early pregnancy. Supplements mainly help if your intake or absorption is low.
How much vitamin B6 and B12 is in TANO THRIVE and IGNITE?
A daily 2-tablet serving of TANO THRIVE contains 6 mg vitamin B6 and 18 mcg B12, plus B3 and B5; TANO IGNITE contains 1.9 mg B6 and 2.2 mcg B12. Taken together that's 7.9 mg B6, below the European upper limit of 12 mg a day. If you also take a B complex or multivitamin, add up the B6 across all products and check with a pharmacist.
Which B vitamin is best for energy?
All eight contribute to energy metabolism, but B12 and folate deficiency are the most common causes of B-vitamin-related tiredness because they affect red blood cells. Taking more than you need won't boost energy. If you're persistently tired, a blood test is more useful than guessing.
Should I take a B complex every day?
Most people who eat a varied diet don't need one. A B complex or multivitamin may be useful for vegetarians, older adults, people on certain medications or those with restricted diets. Choose moderate doses and check total B6 across all products.
Why does my urine turn bright yellow after taking B vitamins?
That's riboflavin (B2), which is naturally yellow-green and excreted in urine when you take more than your body needs at once. It's harmless. It's also a visible reminder that extra water-soluble vitamins are often simply excreted.
Do vegetarians need B12 supplements?
Often, yes. B12 is found almost exclusively in animal foods, and plant sources like tempeh or seaweed are not reliable. Vegetarians who eat dairy and eggs may get some, but vegans in particular need fortified foods or a supplement. A doctor can check your levels.