Vitamin B6 Deficiency in India — Symptoms, Causes & Why the Active Form Matters | EVO HOMINUS
Nutrition Science Hub

The tingling in your hands
might be a vitamin, not nerves.

Vitamin B6 deficiency shows up as fatigue, irritability, cracked lips, and — most distinctively — tingling or numbness in the hands and feet. It’s common in people on TB treatment, low-protein diets, and pregnancy, and it’s also one of the only B vitamins where too much causes the very same nerve symptoms as too little. Here’s what it is, why it happens, and why the form matters.

By EVO HOMINUS Nutrition Science Updated July 2026 11 min read
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2.4 mg
ICMR-NIN 2020 adult RDA for Vitamin B6 per day
ICMR-NIN Recommended Dietary Allowances, 2020
100+
enzymatic reactions in the body that depend on active vitamin B6
Vitamin B6 coenzyme function, nutritional biochemistry literature
2.8M+
new TB cases diagnosed in India each year, most treated with isoniazid — a known B6 depleter
WHO Global Tuberculosis Report
100 mg
NIH’s upper limit for supplemental B6 — yet nerve symptoms are reported at doses well below it
NIH Office of Dietary Supplements, Vitamin B6 Fact Sheet

What vitamin B6 actually does

Vitamin B6, in its active coenzyme form, participates in more than 100 enzymatic reactions across the body — more than almost any other single vitamin. Its core roles: helping metabolize the protein you eat into usable amino acids, synthesizing the neurotransmitters serotonin, dopamine, and GABA that regulate mood and sleep, supporting the production of hemoglobin for oxygen transport, and contributing to normal immune function.

Because B6 touches so many systems at once, a deficiency rarely shows up as one single, obvious symptom. Instead it tends to appear as a cluster — nerve symptoms, skin changes, low mood, and fatigue — that’s easy to attribute to something else entirely.

Why vitamin B6 deficiency happens

Unlike some nutrient gaps that come down almost entirely to diet, B6 deficiency in India has several distinct drivers, and one of them is specific enough to be worth knowing by name.

“Isoniazid doesn’t just fail to provide B6 — it actively destroys it, by binding directly to the vitamin’s active form.”

Mechanism of isoniazid-induced pyridoxine depletion

The main drivers of vitamin B6 deficiency

Each factor reduces usable B6 status through a distinct mechanism

Isoniazid →
↓
Direct chemical depletion of B6 Isoniazid, the first-line tuberculosis drug used across India’s large TB treatment program, binds directly to pyridoxal phosphate (active B6), forming an inactive complex. This is exactly why doctors routinely co-prescribe pyridoxine alongside isoniazid therapy.
Hydrazone complex formation
Low protein diversity →
↓
Reduced dietary B6 intake B6 is present across meat, fish, poultry, legumes, bananas, and potatoes — diets low in variety or heavily reliant on refined carbohydrates tend to fall short of adequate intake over time.
Insufficient dietary supply
Alcohol use →
↓
Increased B6 breakdown Chronic alcohol use interferes with the storage of active B6 in the liver and accelerates its breakdown, lowering circulating levels even when dietary intake is otherwise adequate.
Hepatic storage disruption
Pregnancy →
↓
Increased requirement and use B6 requirements rise during pregnancy, and it’s also commonly used therapeutically (often combined with doxylamine) to manage nausea — both factors that can draw down existing reserves.
Higher physiological demand
Kidney disease →
↓
Altered B6 metabolism Chronic kidney disease affects the activation and clearance of B6, and is independently associated with lower circulating active B6 levels in affected patients.
Impaired metabolism/clearance

The symptoms — and why the nerve one stands out

Most B6 deficiency symptoms are easy to miss individually. One of them, though, is distinctive enough to be worth flagging on its own.

01
Fatigue and irritability Often the earliest and least specific symptom — commonly attributed to stress or poor sleep rather than a nutrient gap.
02
Tingling or numbness in the hands and feet Peripheral neuropathy from B6 deficiency is a genuinely distinctive symptom — worth mentioning to a doctor specifically, especially if you’re on isoniazid or another B6-depleting medication.
03
Cracked corners of the mouth and a sore, swollen tongue Known clinically as cheilosis and glossitis — visible signs that often prompt people to check for a B-vitamin gap more broadly.
04
Microcytic anemia B6 is required for hemoglobin synthesis; deficiency can contribute to small, low-hemoglobin red blood cells detectable on a routine complete blood count.
05
Weakened immune response B6 supports normal immune cell function; low status has been associated with reduced immune resilience in nutrition research.

Who’s most at risk

Higher risk — worth discussing with a doctor

These factors independently raise the odds of low B6 status

People currently on isoniazid for tuberculosis treatment
Pregnant women, particularly those using B6 therapeutically for nausea
Older adults with reduced dietary diversity or nutrient absorption
Heavy or long-term alcohol users
People with chronic kidney disease
People on certain long-term blood pressure medications or anticonvulsants

Generally lower risk — still worth a baseline check

Lower risk on paper doesn’t guarantee sufficiency — test to confirm

People eating a varied, protein-inclusive diet regularly
People not on any medication known to interact with B6
People with no chronic kidney or liver condition
People without persistent, unexplained tingling or numbness in hands or feet

Why more B6 isn’t automatically better

An Important Exception

Unlike most B vitamins, B6 has a real excess risk

For nutrients like B12 or K2, there’s essentially no established downside to generous daily doses — the body simply uses what it needs and clears the rest. Vitamin B6 doesn’t follow that pattern. While NIH’s tolerable upper limit for supplemental B6 is set at 100 mg/day, case reports of sensory peripheral neuropathy — numbness and tingling, the very symptom seen in deficiency — have been documented at chronic daily doses well below that figure, which is why several health authorities recommend more conservative long-term intake limits than the NIH ceiling alone would suggest.

This is precisely why a daily multivitamin dosing B6 at a sensible maintenance level — not a mega-dose “for energy” — is the safer long-term choice, especially for a product meant to be taken every day, indefinitely.

Why the active form — P5P — matters

Standard pyridoxine (commonly as pyridoxine hydrochloride) is biologically inert until the liver converts it into Pyridoxal-5′-Phosphate (P5P), the active coenzyme form your body actually uses in those 100+ reactions. P5P is already in that active form, skipping the conversion step — a meaningful distinction for older adults, people with reduced liver function, or anyone whose conversion capacity may already be under strain from medication or illness.

How EVO HOMINUS Addresses This

Active P5P. At exactly 100% RDA — never more.

EVO HOMINUS uses Pyridoxal-5′-Phosphate (P5P) — the active coenzyme form of Vitamin B6 — dosed at exactly the ICMR-NIN 2020 adult RDA of 2.4 mg, deliberately not a mega-dose. Given the documented nerve-related risk of chronic high-dose B6, this is a formulation choice made specifically because EVO HOMINUS is designed for daily, indefinite use, not a short-term energy boost. It sits alongside methylcobalamin B12, Quatrefolic® methylfolate, and vegan D3 in a single vegetarian capsule — active forms throughout, at sensible, RDA-anchored doses.

Pyridoxal-5′-Phosphate (P5P) 100% ICMR-NIN 2020 RDA Methylcobalamin B12 Quatrefolic® Methylfolate Vitashine® Vegan D3 Zero Fillers · Vegetarian Capsule
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What to actually do about it

01
If you’re on isoniazid or another B6-interacting medication, ask your doctor directly Co-prescribing pyridoxine alongside isoniazid is standard practice precisely to prevent this deficiency — if it hasn’t come up, raise it with your treating physician.
02
Note persistent tingling or numbness and mention it to a doctor This symptom is distinctive enough to be worth flagging specifically, rather than assuming it’s general fatigue or poor circulation.
03
Eat a varied, protein-inclusive diet Poultry, fish, legumes, potatoes, and bananas are all solid dietary B6 sources — variety matters more than any single “superfood.”
04
Avoid unsupervised B6 mega-dosing Be cautious with “energy” supplements or stand-alone B6 products dosed well above RDA for long-term daily use — the nerve-symptom risk at chronic high doses is real, and a maintenance-level daily multivitamin is the more sensible long-term choice.
05
Take a daily multivitamin with active P5P at a sensible dose For ongoing daily support, an RDA-anchored dose of active P5P covers routine requirements without approaching the range associated with nerve-related side effects.
Common Questions

Vitamin B6 deficiency, answered plainly.

Vitamin B6, in its active coenzyme form, is involved in more than 100 enzymatic reactions — most centrally, amino acid metabolism, synthesis of neurotransmitters including serotonin, dopamine, and GABA, hemoglobin production, and normal immune function.

Low dietary protein and food diversity, heavy alcohol use, kidney disease, malabsorption, and certain medications — most notably isoniazid, the first-line tuberculosis drug — along with some blood pressure medications and long-term anticonvulsant use. Pregnancy also increases requirements.

Fatigue and irritability, tingling or numbness in the hands and feet, cracked corners of the mouth and a sore tongue, microcytic anemia, and a weakened immune response. A blood test is the reliable way to confirm B6 status specifically.

Isoniazid binds directly to pyridoxal phosphate (active B6), forming an inactive complex and depleting usable B6. India diagnoses millions of new TB cases yearly, nearly all treated with isoniazid — which is why doctors routinely co-prescribe pyridoxine alongside TB treatment.

ICMR-NIN’s 2020 RDA for adults is 2.4 mg per day. Anyone on a B6-depleting medication like isoniazid should follow their doctor’s specific guidance rather than the general RDA alone.

Yes — unusual among B vitamins. NIH’s upper limit is 100 mg/day, but case reports of sensory peripheral neuropathy have been documented at chronic doses well below that, which is why conservative long-term intake is recommended rather than assuming more is better.

Standard pyridoxine must be converted by the liver into Pyridoxal-5′-Phosphate (P5P) before it’s biologically active. P5P is already in that active form, skipping the conversion step — relevant for older adults or anyone with reduced liver conversion capacity.

People currently on isoniazid for TB treatment, pregnant women, older adults with reduced dietary diversity, heavy alcohol users, people with kidney disease, and people on certain long-term blood pressure or anticonvulsant medications.

EVO HOMINUS delivers P5P at exactly the ICMR-NIN 2020 adult RDA of 2.4 mg — a maintenance dose, not a mega-dose. Given the documented nerve-symptom risk at chronic high-dose B6, dosing at RDA is a deliberate choice for a supplement meant for daily, long-term use.
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