Tingling hands, cracked lips,
could it be vitamin B6?

What vitamin B6 does in your body

Vitamin B6 is a family of six related forms. The one your cells actually use is pyridoxal 5′-phosphate (P5P, also called PLP). It works like a key that switches on more than 100 enzymes, mostly the ones that handle protein.1 That is why your need for B6 rises when you eat more protein, and why a shortfall shows up in so many places at once: skin, mood, blood and nerves.

Vitamin B6 contributes to normal energy-yielding metabolism, the normal functioning of the nervous system, normal psychological function, normal red blood cell formation, normal immune function, normal homocysteine metabolism, normal protein and glycogen metabolism, the regulation of hormonal activity and the reduction of tiredness and fatigue.2

Vitamin B6 deficiency in India: how common is it?

India’s big nutrition surveys have focused on iron, B12, folate and vitamins A and D, so reliable national figures for B6 are scarce. The best large dataset comes from the United States, where blood tests found about 1 in 4 adults who took no supplements had low B6, and three in four women on the contraceptive pill who took no B6 supplement were low.3 In a Canadian study, women of South Asian descent had lower active B6 than women of European descent.4

Two Indian facts raise the stakes. First, India has the world’s largest TB burden, with about 27.1 lakh new cases in 2024, roughly a quarter of all cases worldwide.5 The main TB medicine, isoniazid, works against vitamin B6. Second, your body needs vitamin B2 (riboflavin) to activate B6, and in a study of 407 healthy adults, people with poorer B2 status had lower active B6, whatever their B6 intake.6 Our vitamin B2 guide explains why low B2 is common in Indian diets.

Vitamin B6 deficiency symptoms

Mild low B6 can go unnoticed for months or even years.1 When signs appear, they usually come as a cluster:

The tingling deserves a closer look, because vitamin B6 is the one B vitamin where both too little and too much can affect the nerves. A 2023 review found the clearest evidence for nerve damage from high-dose supplements, while the link with low B6 was weaker.7 So if your feet tingle and you take a B-complex, a “nerve” tonic or high-dose B6, mention every product to your doctor. Many other causes, especially low B12 and diabetes, are more common; our tingling hands and feet guide covers them. Cracked lips and a sore tongue also point to low vitamin B2 or iron, so test rather than guess.8

What causes low vitamin B6

• Heavy drinking — alcohol speeds up B6 breakdown, and active B6 tends to be very low in people who depend on alcohol.1,8
• Kidney disease and dialysis — low active B6 is common in chronic kidney disease, on dialysis and after a kidney transplant.1
• Gut and autoimmune conditions — coeliac disease, Crohn’s disease, ulcerative colitis and rheumatoid arthritis are all linked with low B6.1
• Older age — in the riboflavin study, low B6 was nearly three times as common in adults over 60 (14%) as in younger adults (5%).6
• The contraceptive pill — strongly linked with low B6 in US data.3
• Pregnancy, obesity and being underweight — all associated with lower B6 status.1
• Certain medicines — listed in the table that follows.

Sources for the medicine list: NIH and the Linus Pauling Institute.1,8 Never stop or change a prescribed medicine on your own.

Isoniazid and vitamin B6: the TB connection

Some of the clearest proof came from India. In the early 1960s, the Tuberculosis Chemotherapy Centre in Madras (today’s ICMR-National Institute for Research in Tuberculosis, Chennai) found that a B-complex tablet giving just 6 mg of pyridoxine a day fully prevented nerve damage in patients on high-dose isoniazid. Nerve problems were more common in “slow inactivators”, people whose bodies clear isoniazid slowly.9 A follow-up study linked the damage to a shortage of active B6 in the blood, and showed that pyridoxine put it right.10

“Six milligrams of B6 a day was enough to protect the nerves of patients on high-dose TB treatment in 1960s Madras.”

The simple version

Today, WHO-approved pyridoxine 10 mg tablets are used to prevent isoniazid nerve damage in people at higher risk: people with diabetes, HIV, kidney failure, malnutrition or alcohol dependence, and pregnant or breastfeeding women.11 India treats lakhs of people with isoniazid every year, for TB itself and as TB prevention for close contacts.5 If you or a family member are on it, ask the treating doctor whether B6 is part of the plan. That is a conversation to have with them, not a supplement to add on your own.

Vitamin B6 rich foods in India

These values come from India’s own food tables (IFCT 2017), measured on raw foods:12

Three things stand out. Whole dals beat split dals: whole chana has nearly twice the B6 of chana dal, and brown rice about three times that of polished white rice.12 Bananas are India’s easiest B6 fruit: one medium banana gives roughly a quarter of a woman’s daily need. And dairy is not a B6 food, so a vegetarian day built on rice, dal, roti and milk can fall short unless whole pulses, fruit and nuts are part of it.

Some plant foods hold part of their B6 in a bound form that your body absorbs only about half as well, so variety matters more than any single “superfood”.8 Canned chickpeas are a standout: one cup gives about 1.1 mg in US food data.1 And vegetarians are not automatically at risk: in a large US survey, vegetarians had B6 levels similar to meat-eaters.13

How much vitamin B6 do you need a day?

India’s figures are higher than the US ones (1.3 mg for most adults under 50).14,1 Under FSSAI rules, a health supplement may provide no more than 100% of the ICMR-NIN requirement for any vitamin per day,15 which for B6 means a few milligrams, a small fraction of every international safety limit. That is the right level for a product meant to be taken every day.

Vitamin B6 toxicity: why more is not better

With vitamin B12 or vitamin C, your body simply clears what it doesn’t need. Vitamin B6 is different. Long-term high doses can cause sensory neuropathy: numbness, tingling or burning in the hands and feet, and in severe cases unsteady walking. Symptoms usually improve after the supplement is stopped.1,7 Regulators have been tightening their limits:

Why the gap between 12 and 100 mg? The older limits were based on nerve damage seen at very high doses. Newer reports suggest some people react at much lower intakes. Europe’s food safety agency set its limit from a dose of about 50 mg a day,16 Australia’s regulator logged 250 reports of possible B6 nerve damage, most since 2023,17 Health Canada found a possible link at 10 mg a day or more,18 and the Dutch monitoring centre has recorded 238 reports, 79 of them with products giving 12 mg a day or less.19

The practical lesson: B6 hides in many products, including B-complex tablets, magnesium blends, energy drinks and “nerve” formulas. Add up the B6 from everything you take, and keep the total near your daily need unless a doctor prescribes more for a specific reason.

P5P vs pyridoxine: does the form of B6 matter?

Most B6 supplements use pyridoxine hydrochloride, which is cheap and stable. Your body turns it into P5P in steps, and the slowest step needs vitamin B2, which many people run low on.6 P5P skips that slow step. Lab research from Maastricht University also found that pyridoxine, not P5P, damaged nerve cells and jammed the enzymes that need active B6, an effect the scientists called the “vitamin B6 paradox”.20

Two honest points stay with any form. Every regulator’s limits and warnings cover B6 in general, P5P included, and what matters most for safety is the daily amount. Our P5P vs pyridoxine guide goes deeper into the forms and how to read a label.

Vitamin B6, mood and stress

Vitamin B6 is the helper your brain uses to make its calming messenger GABA and its mood messengers serotonin and dopamine.1 That is why low B6 can show up as irritability, a short fuse or low mood.

B6 and magnesium make a good team. In a trial of 264 stressed adults with low magnesium, both magnesium alone and magnesium with B6 cut stress scores by more than 40% over eight weeks. In people with severe stress, adding B6 gave 24% more improvement than magnesium alone.21 A UK trial in stressed young adults found that a high dose of B6 for a month reduced anxiety, though the researchers called the work early-stage.22 Our magnesium for anxiety and stress guide covers the magnesium side. These findings are about everyday stress and mood, not anxiety disorders or depression, which need a doctor.

Vitamin B6 in pregnancy and morning sickness

Pregnancy raises the B6 requirement to 2.3 mg a day in India.14 For nausea, the American College of Obstetricians and Gynecologists suggests 10–25 mg of B6 three or four times a day, adding doxylamine if needed, and in trials B6 combined with doxylamine reduced nausea and vomiting by about 70%.1 These are medicine-level doses, prescribed for a few weeks, and doxylamine-and-B6 tablets are prescription medicines in many countries.18 For other pregnancy outcomes, a Cochrane review found too few trials to show a benefit from routine B6 tablets.23 If you are pregnant or planning, ask your obstetrician before taking any B6 beyond a prenatal vitamin.

How to test your vitamin B6 level

The 20 nmol/L cut-off is the one the US Food and Nutrition Board used to set its requirements, and 30 nmol/L is the traditional mark of good status.1,6 Labs set their own ranges, and conditions such as rheumatoid arthritis can lower PLP without a true shortage, so your doctor will read the result alongside your symptoms and a blood count.1 Most people never need this test; it is most useful when tingling, an unexplained small-cell anaemia or one of the risk factors in this guide is present.

What to actually do about low vitamin B6

1. See a doctor about tingling or numbnessNerve symptoms need a proper check, because low B12, diabetes, thyroid problems and too much B6 can all cause them.
2. Review your medicinesIf you take isoniazid, cycloserine, an epilepsy medicine, theophylline, penicillamine or the contraceptive pill, ask whether you need extra B6.
3. Eat B6-rich foods every dayWhole dals and beans, a banana, a handful of pistachios, sunflower seeds or walnuts, whole grains, and chicken, fish or eggs if you eat them.
4. Keep vitamin B2 up tooMilk, curd, eggs and green leafy vegetables supply the riboflavin your body needs to activate B6.
5. Add up the B6 in your supplementsCount the B6 in every B-complex, magnesium, energy or nerve product, and keep the total near your daily need unless a doctor prescribes more.
6. Cut back on alcoholHeavy drinking drains active B6, along with B1, folate and magnesium.

A daily supplement built to Indian requirements is designed to maintain healthy B6 levels; correcting a diagnosed deficiency is your doctor’s job, with a dose and duration matched to the cause.

Claims are ingredient-based and not specific to any product. Details of each study are in “About the studies” just below.