How much B6 is too much? Check the dose in your B complex

What the B6 checker works out

The checker multiplies the B6 in one capsule by the number of capsules you take and compares the total with EFSA’s 12 mg limit. The bar fills up to that limit, and the verdict tells you whether the dose is sensible for months of use.

Vitamin B6 is in many supplements, often at doses dozens of times above what you need. In “B-50” and “B-100” complexes, the number means 50 or 100 mg of most B vitamins, B6 included. Magnesium with B6, ZMA and multivitamins contain less, but together with a complex the total soon passes 10 mg.

How much B6 you need

The NHS says most people get enough B6 from a varied diet. US data put average intake at about 1.5 mg for women and 2 mg for men. Poultry, beef, chickpeas, potatoes, non-citrus fruit and fortified cereals are good sources. Deficiency is uncommon in healthy people eating a normal diet.

The gap between what you need and what’s in the bottle is easier to see on a scale:

How to use the checker

1. Find the Vitamin B6 line on the label. The form is usually in brackets: pyridoxine HCl or pyridoxal-5-phosphate (P-5-P).
2. Check the serving size. If the figure is for 2 capsules, halve it.
3. Enter the B6 per capsule in milligrams in the first box.
4. Enter how many capsules you take a day.
5. If another supplement also contains B6, check it separately and add the totals.

How to read the result

The big number is the B6 you get from the supplement each day. The checker doesn’t add food, so allow another 1.5–2 mg on top.

B6 toxicity: why too much is a problem

The main risk is peripheral neuropathy (damage to the nerves in the hands and feet). It shows up as numbness, tingling, burning, loss of feeling and an unsteady walk.

• Severe cases have been described with 1–6 g a day taken for a year or more.
• Reports exist at lower doses too. Lareb, the Dutch pharmacovigilance centre, reviewed 90 cases of neuropathy linked to products containing 1.4 to 100 mg of B6 per tablet. Evidence below 50 mg a day is limited, but the risk can’t be ruled out.
• EFSA’s limit rests on this. It took 50 mg a day from a case–control study as its starting point and applied a safety factor of 4, giving 12 mg.

Symptoms usually go away if you stop promptly. After many months of high doses, Food Standards Scotland notes they can be permanent.

Limits and when to see a doctor

• The checker doesn’t add B6 from food or allow for a prescribed dose.
• Treatment doses of B6 for specific conditions should only come from a doctor.
• High-dose B6 (around 200 mg a day) may lower blood levels of the epilepsy medicines phenytoin and phenobarbital. If you take them, check any B6 product with your doctor.
• EFSA’s 12 mg limit also applies in pregnancy. Count the B6 in your pregnancy vitamin before adding magnesium with B6 or a B complex.
• Numbness or tingling in your hands or feet while taking supplements means stop and see your GP.

How to choose a B complex on iHerb

1. Decide whether you need a complex at all. Vegans, people over 50 and those on metformin often need only B12.
2. Open the Supplement Facts panel on the product page and find the Vitamin B6 line.
3. Run the checker for every product that contains B6.
4. Choose a product with no more than 10 mg of B6 per daily serving.

Who needs which B vitamins is covered in our guide to vitamin B complex. If you take magnesium with B6, check that too. For other doses, try the zinc calculator and the omega-3 dose calculator.