Vitamin B6: Daily Needs, Food Sources & Deficiency

At a glance

Women, 19-50

1.3 mg (1.5 mg at 51+)

Men, 19-50

1.3 mg (1.7 mg at 51+)

Upper limit (adults)

100 mg/day

How common is deficiency?

Uncommon overt deficiency; marginal status occurs in some older adults, women, and alcohol users

Food sources

Animal sources

Chicken, turkey, beef, tuna, salmon, liver, eggs

Plant sources

Chickpeas, potatoes, bananas, fortified cereals, pistachios, sunflower seeds, avocado, spinach

Deficiency and testing

Signs of deficiency

Microcytic anemia, seborrheic dermatitis, cracked lips, glossitis, depression/confusion, peripheral neuropathy, seizures (infants)

Who is at higher risk

Older adults, alcohol use disorder, kidney disease/dialysis, autoimmune disorders, obesity, drugs (isoniazid, penicillamine, some anticonvulsants)

How it is tested

Plasma pyridoxal 5'-phosphate (PLP) by HPLC; erythrocyte aspartate transaminase stimulation (EAST); urinary 4-pyridoxic acid; tryptophan load test

Cut-offs

Plasma PLP <20 nmol/L = inadequate (<30 nmol/L often used as borderline)

Symptoms are not specific. Only a clinician with the right tests can tell whether you are deficient.

Supplement forms

Common forms

pyridoxine HCl, pyridoxal 5'-phosphate (P5P, 'active'), pyridoxamine.

More effective

pyridoxine HCl at or near the RDA (converted well by most people, inexpensive, best studied); P5P is a reasonable choice for people with impaired conversion (liver disease, some genetic variants) or who prefer the active form.

Less effective

high-dose pyridoxine long term (over 100 mg/day can cause nerve damage; keep supplements near the RDA unless prescribed); claims that P5P is always superior or always safer (data are limited).

Safety, interactions and halal notes

Safety and interactions

Upper limit for adults: 100 mg/day. Going above the upper limit over time can cause harm, so check labels and talk to a clinician before high-dose supplements.

Halal note

The nutrient itself is not a halal question. For supplements, check the delivery form: gelatin (pork or non-halal bovine), capsule shells, glycerin, and alcohol-based carriers need halal certification. Ask for the halal certificate, not just a label claim. This is general guidance, not a certification.

Frequently asked questions

How much Vitamin B6 do adults need per day?

Women 19-50: 1.3 mg (1.5 mg at 51+). Men 19-50: 1.3 mg (1.7 mg at 51+). Upper limit: 100 mg/day. Needs change with age, pregnancy and health conditions.

What are the signs of Vitamin B6 deficiency?

Microcytic anemia, seborrheic dermatitis, cracked lips, glossitis, depression/confusion, peripheral neuropathy, seizures (infants). These signs are not specific, so only a clinician with the right tests can confirm a deficiency.

What are the best food sources of Vitamin B6?

Animal sources: Chicken, turkey, beef, tuna, salmon, liver, eggs. Plant sources: Chickpeas, potatoes, bananas, fortified cereals, pistachios, sunflower seeds, avocado, spinach.

Which form of Vitamin B6 supplement is best?

pyridoxine HCl at or near the RDA (converted well by most people, inexpensive, best studied); P5P is a reasonable choice for people with impaired conversion (liver disease, some genetic variants) or who prefer the active form.

Related nutrients

Sources

NIH Office of Dietary Supplements fact sheet