Numbness, tingling, burning or pins and needles in the feet — often worse at night, often creeping upwards over months — is peripheral neuropathy. It is common, it becomes more common with age, and the single most useful thing to know is that several of its causes are found with cheap blood tests and are treatable once found.
One of those causes is a supplement. We sell two products that contain the nutrient in question, so that section is about us as much as anyone, and it's not buried at the bottom.
What it feels like, and why the pattern matters
The classic distribution is "stocking-glove" — starting in the toes and feet, symmetrical on both sides, spreading upward, and reaching the hands later. That pattern reflects the fact that the longest nerves fail first, which is why it starts at the furthest point from the spine.
Symptoms split roughly into two groups, and both can be present:
- Small-fibre symptoms — burning, prickling, electric or shooting pain, sensitivity to light touch, and loss of temperature sensation. Often the earliest thing to go is the ability to tell warm from cool in the toes.
- Large-fibre symptoms — numbness, loss of vibration sense and position sense, unsteadiness in the dark, and a feeling of walking on cotton wool or gravel.
Asymmetry, rapid onset, or weakness rather than sensory change is a different picture and needs seeing sooner — see the red flags near the end.
Why it matters beyond the discomfort
Two consequences are easy to underrate. Loss of protective sensation means injuries go unnoticed — a blister, a stone in a shoe, water that's too hot. In diabetes this is the pathway to foot ulcers and, in the worst case, amputation, and it is why diabetic foot checks exist. And loss of position sense causes falls, particularly at night or on uneven ground, because you lose the information your balance was relying on.
The causes, ordered by how findable they are
Diabetes and prediabetes
The most common cause in high-income countries, and it develops in a substantial proportion of people with diabetes over time. The important, less-known part: impaired glucose tolerance short of diabetes is also associated with neuropathy, so glucose is worth investigating properly rather than dismissing on one borderline result. If HbA1c comes back near the top of normal and you have unexplained neuropathy, that's a reason to ask what else could be done to assess glucose handling rather than to stop.
This sits inside the same vascular-metabolic cluster that drives stroke risk and dementia risk — which means the work you'd do for one is the work you'd do for all three.
Vitamin B12 deficiency
A genuinely treatable cause, and one that is missed for a specific reason: B12 deficiency can cause neurological damage before it causes anaemia, so a normal full blood count has not excluded it.
Higher risk if you are over 60, vegetarian or vegan, take metformin or long-term acid-reducing medication, or have had gastric or bowel surgery. And serum B12 is an imperfect test — if yours sits low-normal with symptoms that fit, the follow-up is a functional marker, methylmalonic acid or homocysteine, which rise when B12 is functionally insufficient. What the B12 trials say, and the wider blood panel worth asking for.
Time matters here. B12-related nerve damage becomes less reversible the longer it runs, which is the argument against watching and waiting on a borderline result.
Alcohol
A direct toxic effect on nerves, compounded by the thiamine deficiency that often accompanies heavy drinking. It is one of the more reversible causes and one of the most under-reported at appointments. The wider picture on alcohol and the brain has shifted, and not in the reassuring direction.
Thyroid dysfunction
An underactive thyroid can cause neuropathy alongside the cognitive and mood symptoms it's better known for. One blood test — details here, including the biotin problem that can distort the result.
Too much vitamin B6 — the one nobody expects
This deserves its own space, because it is the cause most likely to be self-inflicted and the least likely to be suspected.
Vitamin B6 is one of the few nutrients with a well-documented dose-dependent neurotoxicity. Excess B6 causes a sensory peripheral neuropathy — and the presentation is the same stocking-glove pattern described at the top of this article, typically beginning with thermal sensation in the toes and progressing to vibration and position sense.
The doses:
- Most reported cases involve large intakes, typically over 2 g/day, taken for months to years.
- But a number of more recent case reports describe neuropathy at doses near or even below the European Food Safety Authority's tolerable upper limit of 25 mg/day.
- For reference, EFSA's upper limit is 25 mg/day; the US Food and Nutrition Board's is 100 mg/day. Those are very different numbers, which is itself worth knowing when reading a label.
The good news: it improves on stopping. Symptoms can continue to progress briefly after discontinuation, but substantial improvement is usually seen within around six months, and most people reach near-complete recovery over two to three years. Vibration sense recovers slowest, and distal sensation is often left somewhat reduced — which is the argument for catching it early rather than assuming it will fully reverse.
Where B6 hides. B-complex vitamins. "Energy" formulas. Products marketed for nerve support — which is darkly ironic, since a high-dose B6 nerve supplement can cause the thing it's sold for. Some magnesium products. Morning sickness preparations. And, frequently, more than one product at once, which is how someone reaches a total they never intended.
Including ours — and here is our position. Two Proco products contain vitamin B6 as pyridoxine hydrochloride: Cognitive Support and Sleep Support. On the current formulas we do not have individual milligram amounts published for it. That is a gap, it is a more consequential gap for B6 than for most ingredients precisely because the toxicity is dose-dependent, and we are not going to write an article about B6-induced neuropathy and leave that out.
Two practical things follow. If you take both Cognitive Support and Sleep Support, you are taking B6 from two sources — the same stacking issue we flag for melatonin across Sleep Formula and Sleep Support. And if you are adding a separate B-complex or a B6 supplement on top of either, check the total with a pharmacist. If you have unexplained numbness or tingling in your feet, bring every supplement you take to that appointment, ours included.
Medication and treatment
Certain chemotherapy agents are a well-known cause, as are some HIV medications, some antibiotics and a handful of other drugs. This is not a reason to stop a treatment — it is a reason for the person prescribing it to know about the symptoms early, because dose adjustments are sometimes possible.
Autoimmune, inflammatory and hereditary causes
Less common but important not to miss, because some are specifically treatable — chronic inflammatory demyelinating polyneuropathy (CIDP) among them. Hereditary neuropathies such as Charcot-Marie-Tooth run in families and often start younger. These are the reason a neurologist's assessment adds something a blood panel doesn't.
And a meaningful share stay unexplained
Even after thorough investigation, a substantial proportion of peripheral neuropathy is labelled idiopathic. That is a frustrating answer, but it is not the same as no answer: it means the treatable causes have been excluded, which changes what happens next.
What to ask for
A reasonable first-line panel, worth naming at the appointment: HbA1c or fasting glucose · vitamin B12 (with a functional marker if borderline) · folate · thyroid function · full blood count · kidney function. Depending on the picture, protein studies, inflammatory markers and autoimmune tests may be added, and nerve conduction studies or a skin biopsy may follow.
And take a full list of everything you take, prescribed or not, with doses where you have them.
What actually helps
Treat the cause where there is one. Glucose control, B12 replacement, stopping alcohol, correcting thyroid function, stopping excess B6. This is the part with the most leverage and it's why the diagnostic work matters.
For the pain itself, neuropathic pain does not respond well to ordinary painkillers. The medications with the evidence are different in kind — certain antidepressants such as duloxetine and amitriptyline, and the gabapentinoids gabapentin and pregabalin. All are prescription decisions with real side-effect profiles, named here only so you know the category exists and that paracetamol not working isn't the end of the road.
Foot care is not a footnote. If protective sensation is reduced: check your feet daily, check the water temperature with your hand or elbow, don't walk barefoot, and get footwear that fits properly. In diabetes this is among the highest-value routine things available.
Alpha-lipoic acid, honestly
The supplement with the most real evidence here, and we don't sell it.
A meta-analysis of 10 randomised trials in 1,242 people with diabetic polyneuropathy, at doses of 600, 1,200 and 1,800 mg/day over periods from three weeks to two years, found a dose-dependent improvement in symptom scores — total symptom score, neurological disability score and global satisfaction.
The honest caveat matters as much as the finding: there was no significant improvement in the objective measures — vibration perception threshold, lower-limb impairment score, or nerve conduction studies. So the fair reading is that it may help how the neuropathy feels without demonstrably changing nerve function. The authors also flag the small number of trials, small samples, and inconsistent outcome measures.
That's a genuine, modest result at doses well above what general supplements contain. If you're considering it, discuss it with whoever manages your diabetes — and note that the trials were in diabetic neuropathy specifically, not neuropathy in general.
Red flags — don't wait
- Rapidly progressive weakness, especially spreading upwards from the legs — this can indicate Guillain-Barré syndrome and is a medical emergency
- Weakness rather than sensory symptoms, or markedly asymmetric symptoms
- Onset over days to weeks rather than months
- Any bladder or bowel change, or a band of numbness around the trunk
- Symptoms following a new medication
- An unnoticed foot wound, or any foot ulcer in someone with diabetes — same-day
Where we sit
Nothing in Proco's range treats peripheral neuropathy. We don't sell alpha-lipoic acid, which is the supplement with the best evidence, and we don't sell B12, which is one of the treatable causes.
What we do sell is two products containing B6 at doses we haven't published — stated above rather than omitted. The broader principle is one we've written about before and are applying to ourselves here: what a label does and doesn't tell you matters most for the ingredients where the dose changes the risk.
If you have numbness or burning in your feet, the useful step is a blood panel and a review of everything you're taking. Not a product.
This article is not medical advice and cannot diagnose neuropathy. Do not stop a prescribed medication on the basis of anything here. If you have diabetes and notice any change in sensation or any wound on your foot, contact your care team promptly.
Sources: Vitamin B6-induced neuropathy: exploring the mechanisms of pyridoxine toxicity — Advances in Nutrition · Effects of oral alpha-lipoic acid treatment on diabetic polyneuropathy: a meta-analysis and systematic review — Nutrients (2023)