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Ingredient guide

Vitamin B6: what it does, how much you need, and the upper limits

Written by the Full Measure editorial team, which sells supplements. Approved for publication by the Full Measure owners. Updated 2026-10-13.

Drafted with AI assistance from the sources listed below. How we write these

Quick answer

Vitamin B6 is a vitamin your body needs for more than 100 enzyme reactions, most of them in protein metabolism. Adults need 1.3 to 1.7 mg a day, and most people in the US get that from food. The US upper limit is 100 mg a day, and European regulators set 12 mg in 2023.^1,2,3

Key facts

Pyridoxine hydrochloride is the most common form in supplements, and absorption is similar across the forms.¹
Chickpeas, tuna, salmon, chicken, potatoes and bananas are among the good food sources.¹
About 28% to 36% of people in the US take a supplement that contains vitamin B6.¹
The upper limits exist because too much B6 from supplements, taken for a long time, can harm the nerves.²
Levodopa and some anti-seizure medicines interact with vitamin B6, so ask first if you take them.^1,4

What vitamin B6 is

The name covers six related compounds: pyridoxine, pyridoxal and pyridoxamine, and a phosphate form of each.¹

The body turns vitamin B6 into pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate, its active coenzyme forms.¹

Vitamin B6 takes part in more than 100 enzyme reactions, most of them concerned with protein metabolism.^1,2

Those reactions reach well beyond protein. The active forms also take part in handling carbohydrates and fats, making neurotransmitters and hemoglobin, and the work of the immune system.¹

What the evidence shows

The five statements below are well-established nutrient functions, each graded moderate, with the amount they refer to. Each is about meeting your needs rather than going beyond them.¹

Vitamin B6 contributes to normal protein metabolism*^1,5

Moderate evidence

This is a well-established nutrient function: vitamin B6 takes part in more than 100 enzyme reactions, most of them concerned with protein metabolism. Most people in the US already get enough from food, so extra is unlikely to add anything.

Amount studied: Recommended intake: 1.3 mg a day for adults up to 50, then 1.5 mg for women and 1.7 mg for men, from food and supplements combined

Vitamin B6 contributes to normal energy-yielding metabolism*^1,5

Moderate evidence

A well-established nutrient function. The active form of vitamin B6 works with enzymes that handle carbohydrates and fats as well as protein, including those that release energy stored as glycogen. European regulators permit this wording for foods that are at least a source of vitamin B6. It does not mean extra B6 gives more energy to someone who already gets enough.

Amount studied: Recommended intake: 1.3 mg a day for adults up to 50, then 1.5 mg for women and 1.7 mg for men, from food and supplements combined

Vitamin B6 contributes to the normal function of the immune system*^1,2,5

Moderate evidence

A well-established nutrient function. NIH lists immune function among vitamin B6's roles, including the production of lymphocytes, a type of white blood cell, and of interleukin 2, a signaling protein. EU regulators permit this wording for foods that are at least a source of the vitamin. The benefit is about getting enough, not about taking more.

Amount studied: Recommended intake: 1.3 mg a day for adults up to 50, then 1.5 mg for women and 1.7 mg for men, from food and supplements combined

Vitamin B6 contributes to normal functioning of the nervous system*^1,2,5

Moderate evidence

A well-established nutrient function. Vitamin B6 is needed to make neurotransmitters, the chemical messengers between nerve cells, and NIH notes its role in brain development during pregnancy and infancy. The EU permits this wording for vitamin B6. NIH notes that B6 supplements, alone or with other B vitamins, do not seem to make a difference to memory or mood in healthy people.

Amount studied: Recommended intake: 1.3 mg a day for adults up to 50, then 1.5 mg for women and 1.7 mg for men, from food and supplements combined

Vitamin B6 contributes to normal red blood cell formation*^1,5

Moderate evidence

A well-established nutrient function. NIH lists hemoglobin formation, the oxygen-carrying protein in red blood cells, among vitamin B6's roles, and the EU permits this wording for vitamin B6. As with its other roles, the benefit comes from getting enough.

Amount studied: Recommended intake: 1.3 mg a day for adults up to 50, then 1.5 mg for women and 1.7 mg for men, from food and supplements combined

How much you need

Adults 19 to 50 need 1.3 mg of vitamin B6 a day.^1,2

From age 51, men need 1.7 mg a day and women 1.5 mg.^1,2

During pregnancy the recommended amount is 1.9 mg a day, and 2.0 mg while breastfeeding.^1,2

On average, US women take in about 1.5 mg of vitamin B6 a day and men about 2 mg.¹

In a 2003 to 2004 national survey, 24% of people who did not take a supplement with vitamin B6 and 11% of those who did had low blood levels of PLP, although most met the recommended intake.¹

So most people meet the recommended amount from food, yet blood tests suggest some still run low. The dosage guide has the amounts for every age.¹

Forms in supplements

Pyridoxine, usually as pyridoxine hydrochloride, is the most common form of vitamin B6 in supplements.^1,2

Some supplements contain pyridoxal 5'-phosphate, one of the two active coenzyme forms the body makes from vitamin B6.¹

Vitamin B6 from supplements is absorbed about as well as vitamin B6 from food, and absorption does not differ much between the forms.¹

The body absorbs large doses of vitamin B6 well but quickly passes most of the excess in urine.¹

Food sources

The richest sources include fish, beef liver and other organ meats, potatoes and other starchy vegetables, and fruit other than citrus.^1,2

US adults get most of their vitamin B6 from fortified cereals, beef, poultry, starchy vegetables and some non-citrus fruits.¹

A cup of canned chickpeas, with 1.1 mg, tops NIH's list. The food guide has the amounts per serving.¹

What's in ours

What’s in ours

Men's Multi: Vitamin B6, 7.5 mg per serving, from the label
Ashwagandha Complex: Vitamin B6, 2.5 mg per serving, from the label
Immune Support: Vitamin B6, 1.7 mg per serving, from the label

Side effects, medicines, and who should ask first

Taking 1 to 6 g of pyridoxine a day for 12 to 40 months can cause severe, progressive sensory neuropathy, with loss of control of body movements. The symptoms usually stop if the supplement is stopped as soon as they appear.^1,2

Other effects of too much vitamin B6 include painful, disfiguring skin patches, sensitivity to sunlight, nausea and heartburn.^1,2

The US upper limit for vitamin B6 is 100 mg a day for adults, counting food and supplements together. It is 80 mg for ages 14 to 18, 60 mg at 9 to 13, 40 mg at 4 to 8 and 30 mg at 1 to 3. In 2023 the European Food Safety Authority set a lower adult limit of 12 mg a day, including during pregnancy and breastfeeding. The US limit does not apply to people taking B6 for medical reasons under a doctor's care.^1,2,3

Ask your pharmacist or doctor first

The carbidopa and levodopa label says pyridoxine at 10 to 25 mg can reverse the effects of levodopa taken on its own, and that carbidopa blocks this. The same label warns that carbidopa and levodopa can lower vitamin B6 levels, that seizures from low B6 have been reported, and that doctors should check B6 levels before and during treatment.⁴

On the medicine's label

Ask your pharmacist or doctor first

Valproic acid, carbamazepine and phenytoin speed up the breakdown of vitamin B6 and can lower its blood levels, which NIH says could reduce the drugs' ability to control seizures. Research also suggests that 200 mg a day of pyridoxine can lower blood levels of phenytoin and phenobarbital; whether smaller amounts do this is not known.^1,2

Reported in studies

NIH also lists cycloserine, an antibiotic used for tuberculosis, and theophylline, a lung medicine, as medicines that interact with vitamin B6 or lower its levels.^1,2

Several of our products contain vitamin B6. If you take more than one, add up the amounts on the labels and compare the total with the limits above.

Ask your doctor first if you are pregnant or breastfeeding and want more than a prenatal vitamin provides¹
Ask first if you have kidney disease, are on dialysis or have had a kidney transplant, because B6 status is often low in these groups^1,2
Stop and see a doctor if you notice changes in sensation or balance while taking vitamin B6¹

Questions people ask

Is vitamin B6 good for your skin?

The sources we use make no skin claim for vitamin B6. NIH lists itchy rashes and scaly skin on the lips among the signs of a shortage, which is uncommon in the US, and too much B6 can cause painful skin patches and sensitivity to sunlight.^1,2

Does vitamin B6 give you energy?

Vitamin B6 is one of the vitamins enzymes use to release energy from food, graded above as a nutrient function. The sources describe no added energy from taking more than you need.¹

Is P5P better than pyridoxine?

NIH says absorption from supplements does not differ much between the forms. Pyridoxal 5'-phosphate, or P5P, is an active form, but the body also turns pyridoxine into it.¹

What does vitamin B6 do for men?

The same roles apply to men and women. Men need 1.3 mg a day up to 50 and 1.7 mg from 51, and on average get about 2 mg a day from food.^1,2

See what we make

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See the Full Measure line Ashwagandha Complex Immune Support Men's Multi

Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.