Vitamin B complex is a supplement that combines the eight B vitamins: B1, B2, B3, B5, B6, B7, B9 and B12. At Probiotic.ie we stock B complex supplements, including formulas with active forms such as methylcobalamin and methylfolate, alongside single B vitamins, shipped from Dublin with tracked delivery across Ireland.
B vitamins: key facts
- There are eight B vitamins, all water-soluble
- Some numbers are missing (B4, B8, B10, B11) because compounds once given those names were later found not to be vitamins
- Vitamin B12 occurs naturally almost only in foods of animal origin
- The B vitamins have more authorised EU health claims than any other vitamin group
- Regulation in Ireland: sold as food supplements under Irish and EU food law, overseen by the Food Safety Authority of Ireland (FSAI)
The eight B vitamins
| Vitamin |
Name |
Forms you may see on labels |
Found in foods such as |
| B1 |
Thiamin |
Thiamin hydrochloride, thiamin mononitrate |
Wholegrains, pork, pulses |
| B2 |
Riboflavin |
Riboflavin, riboflavin-5'-phosphate |
Milk, eggs, fortified cereals |
| B3 |
Niacin |
Nicotinamide (niacinamide), nicotinic acid |
Meat, fish, wheat flour |
| B5 |
Pantothenic acid |
Calcium pantothenate |
Chicken, eggs, mushrooms |
| B6 |
Pyridoxine |
Pyridoxine hydrochloride, pyridoxal-5'-phosphate (P-5-P) |
Poultry, fish, potatoes |
| B7 |
Biotin |
D-biotin |
Eggs, nuts, seeds |
| B9 |
Folate |
Folic acid, L-methylfolate (5-MTHF) |
Leafy greens, pulses, fortified foods |
| B12 |
Cobalamin |
Cyanocobalamin, methylcobalamin |
Meat, fish, eggs, dairy |
What B vitamins contribute to (EU-authorised health claims)
- Thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, vitamin B12 and biotin contribute to normal energy-yielding metabolism.
- Riboflavin, niacin, pantothenic acid, vitamin B6, folate and vitamin B12 contribute to the reduction of tiredness and fatigue.
- Thiamin, niacin, vitamin B6, folate, vitamin B12 and biotin contribute to normal psychological function.
- Vitamin B6 and vitamin B12 contribute to the normal function of the immune system.
- Folate contributes to maternal tissue growth during pregnancy.
These claims apply when a product provides at least 15% of the Nutrient Reference Value (NRV) for the vitamin per daily serving.
Active and methylated B vitamins
Some B complex products use forms such as methylcobalamin (B12), pyridoxal-5'-phosphate (B6) and L-methylfolate (B9). These are often marketed as "active" or "methylated" B vitamins. They are permitted forms of each vitamin in EU food supplements.
"Active" and "methylated" are marketing terms, not regulated categories. All permitted forms count as the same vitamin for labelling and for the authorised health claims. Choose based on the form you prefer and the amount per serving.
B vitamin supplements available in Ireland
| Product |
Type |
Key forms |
Capsule |
Label serving |
| Doctor's Best Fully Active B Complex, 30 capsules |
B complex, all 8 plus vitamin C |
Methylcobalamin 1,000 mcg, Quatrefolic® methylfolate 400 mcg, P-5-P |
Vegetable |
1 capsule daily, with food |
| Life Extension BioActive Complete B-Complex, 60 capsules |
B complex |
Active forms, see label |
Vegetable |
See label |
| NOW Foods B-100 Complex |
B complex, all 8 plus choline and inositol |
See label |
Vegan |
1 capsule daily, with food |
| NOW Methyl B-12 1,000 mcg, 100 lozenges |
Single: B12 |
Methylcobalamin |
Lozenge |
See label |
| Jarrow Formulas Methyl Folate 400 mcg, 60 capsules |
Single: B9 |
L-methylfolate |
Vegetable |
See label |
| Swanson Biotin 5,000 mcg, 100 capsules |
Single: B7 |
D-biotin |
See label |
See label |
| Swanson Vitamin B2 (Riboflavin) 100 mg, 100 capsules |
Single: B2 |
Riboflavin |
See label |
See label |
Figures are as stated by each manufacturer. Always check the label for the amount of each vitamin and its % NRV.
How to choose a vitamin B supplement
1. Complex or single vitamin
A B complex provides all eight B vitamins together. A single B vitamin, such as B12 or folate, provides one. Choose a single vitamin if you only want one, and a complex if you want the full group.
2. Amount per serving and % NRV
Compare the amount of each vitamin and its % NRV on the label. Amounts vary widely between products.
3. Form
Check whether B12 is cyanocobalamin or methylcobalamin, and whether folate is folic acid or L-methylfolate. All are permitted forms.
4. Format
B vitamins come as capsules, tablets, lozenges and sprays. Lozenges dissolve in the mouth, which some people find easier than swallowing capsules.
Folic acid and pregnancy. The HSE advises women who could become pregnant to take a 400 mcg folic acid supplement daily. Speak to your GP or pharmacist about which product is right for you.
Food supplement notice. These products are food supplements, not medicines, and are not intended to diagnose, treat, cure or prevent any disease. Food supplements should not replace a varied, balanced diet and a healthy lifestyle. Do not exceed the recommended daily dose. If you are pregnant, breastfeeding, taking medication or under medical supervision, speak to your GP or pharmacist before use. For health information in Ireland, the HSE is the appropriate reference.
Buying vitamin B in Ireland
All stock ships from Dublin on a tracked service, with free tracked Irish delivery on orders over €75. Because orders ship from within Ireland, no customs charges apply. See our delivery information for details.
Vitamin B FAQs
What is vitamin B complex?
Vitamin B complex is a supplement containing all eight B vitamins: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), vitamin B6, biotin (B7), folate (B9) and vitamin B12.
What do B vitamins do?
B vitamins contribute to normal energy-yielding metabolism, and several contribute to the reduction of tiredness and fatigue and to normal psychological function. These are authorised EU health claims. The exact claims differ for each B vitamin.
Why are there no vitamins B4, B8, B10 or B11?
Those names were given to compounds that were later found not to be true vitamins, so they were dropped. That leaves eight B vitamins with non-consecutive numbers.
What is the difference between folic acid and methylfolate?
Both are forms of vitamin B9. Folic acid is the synthetic form used in most supplements and fortified foods. L-methylfolate (5-MTHF) is the form of folate found in the blood. Both are permitted in EU food supplements. HSE pregnancy guidance refers to folic acid.
What is the difference between cyanocobalamin and methylcobalamin?
Both are forms of vitamin B12 permitted in EU food supplements. Cyanocobalamin is the most common form in supplements and fortified foods. Methylcobalamin is often sold as an "active" form.
Which foods contain B vitamins?
Meat, fish, eggs, dairy, wholegrains, pulses and leafy green vegetables all provide B vitamins. Vitamin B12 occurs naturally almost only in animal foods, so people following a vegan diet often rely on fortified foods or supplements.
Why does vitamin B make urine bright yellow?
Riboflavin (vitamin B2) is naturally bright yellow. Any the body does not use is passed in urine, which can turn it a vivid yellow. This is expected when taking products containing riboflavin.
Are there any side effects of vitamin B complex?
Follow the label and do not exceed the recommended daily dose. Some forms of niacin (nicotinic acid) can cause temporary skin flushing. Long-term high intakes of vitamin B6 are not advised. If you take medication, speak to your GP or pharmacist before use.
When should I take vitamin B complex?
Follow the directions on the label. Many B complex products direct one capsule daily with food.
Are B vitamin supplements vegan?
Many are. NOW Foods B-100 Complex is vegan, and Doctor's Best and Life Extension use vegetable capsules. Check the label for the capsule type and any other ingredients.
Where can I buy vitamin B complex in Ireland?
You can buy vitamin B complex and single B vitamins at Probiotic.ie. Orders ship from Dublin with tracked Irish delivery, and no customs charges apply.
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