B12
Vitamin B12 and Nerves: Metformin, Blood Tests and Why Flow Nerves Does Not Name It
NIH says a vitamin B12 shortage can make hands and feet numb or tingly, and that metformin and acid-reducing medicines can lower B12 absorption. Flow Nerves names six ingredients and none of them is vitamin B12.
Written by the Flow Nerves label deskUpdated
The link01
How is vitamin B12 linked to nerves?
B12 helps keep blood and nerve cells healthy, and a shortage can make your hands and feet numb or tingly.
That is the plain statement from the NIH Office of Dietary Supplements consumer sheet 1. NINDS also names vitamin B12 deficiency among the best-documented nutrition causes of peripheral neuropathy 2, and Cleveland Clinic lists B12 among several vitamins and nutrients whose shortage can cause it, along with copper, B1, B6, B9 and E 3. Of all the nutrition links to numb hands and feet, B12 is the one most worth checking.
That is why it is odd that a product aimed at the nerve endings in the hands, feet and legs names no B12. The six names in Flow Nerves are magnesium glycinate, alpha lipoic acid, butcher's broom root extract, L-carnitine, turmeric extract and coenzyme Q10. If your own tingling comes from a B12 shortage, this capsule would not address it.
Medicines02
Which medicines can lower B12?
| Medicine type | What the sources say |
|---|---|
| Metformin | Can block B12 absorption; observational studies link metformin use with lower B12 and more neuropathy; periodic B12 monitoring is recommended 4 |
| Acid-reducing medicines | Can lower B12 absorption; tell your doctor and pharmacist about supplements and medicines 1 |
| Proton pump inhibitors | Along with age, they speed loss of B12 stores 4 |
If you take any of these, ask whether a B12 check suits you. Keep taking the medicine exactly as prescribed, because stopping it can cause its own problems.
Tests03
What can a test show, and what should you ask?
A blood test can show whether your B12 level is low, and your clinician decides what to do about it.
Ask whether a B12 check suits you
Especially if you take metformin or an acid reducer, or have numb feet or hands.
Bring your medicine list
Include doses and how long you have taken each one.
Ask about the plan
If the level is low, ask how it will be treated and rechecked.
Do not self-dose to guess
Taking a supplement before a test can blur the result.
We do not give B12 doses, because a safe dose depends on the cause and on you. That belongs to a clinician.
Fit04
Where does Flow Nerves fit?
It does not replace a B12 plan, and it does not claim to.
If your clinician finds a B12 shortage, the treatment is for that shortage. A capsule of six other names does not change that. If you also want to try a product like Flow Nerves, tell your clinician, and check the cautions on each ingredient. The ingredients page shows what the six names are, and the medicines guide gives the pharmacist questions.
Flow Nerves is a dietary supplement, not a drug and not a neuropathy medicine. Ask your doctor or pharmacist first if you take diabetes medicine or insulin, a blood thinner, blood pressure medicine, an antibiotic or any other prescription, if you have kidney or liver disease, or if you are pregnant, nursing or under 18. Keep taking prescribed medicine, and keep your checkups. See side effects and interactions.
Red flags05
When should you not wait for a test?
If symptoms are sudden, spreading or come with weakness, trouble walking or confusion.
- Sudden weakness, a drooping face or trouble speakingCall 911. These are stroke signs, and every minute counts. Do not drive yourself. 5
- Weakness that spreads over hours or daysGet urgent care. Fast-spreading weakness can be Guillain-Barre syndrome, which is treated in hospital. 6
- A numb foot with a sore that will not healSee a clinician promptly, especially with diabetes. Feet that cannot feel can hide cuts that get infected. 7
- Shaky, sweaty, confused or faintPossible low blood sugar, which alpha lipoic acid can add to when you take diabetes medicine. Treat it as an emergency if severe. 8
- Yellow skin or eyes, dark urine, belly painPossible liver trouble. Liver injury has been reported with high-absorption turmeric products. Stop and call a clinician. 9
- Unusual bruising or bleedingTurmeric, CoQ10 and L-carnitine can matter with blood thinners. Call your prescriber. 10
- Chest pain, trouble breathing, swelling of lips or faceCall 911. Possible heart problem or allergic reaction. 11
This list is not complete, and a supplement is never a reason to wait.
Flow Nerves: 30 capsules a bottle1 capsule a day with a meal · from $49 a bottle · 60-day guarantee (confirm)
See packsWho06
Who is more likely to run low on B12?
People who take certain medicines, older adults, and people whose diet or gut limits how much B12 they absorb.
The NIH sheet explains that B12 comes from animal foods and fortified foods, and that some people struggle to absorb it even when they eat enough 1. A PubMed review on metformin adds that age and long-term use of acid-reducing medicine speed the loss of stores 4. None of that means you are low. It means the question is worth raising if you already have numb or tingling feet or hands and any of these apply to you.
It also helps to know that low B12 is only one of several nutrient and medical causes. Our causes guide lists the wider set, because a clinician will look across all of them rather than at one vitamin in isolation. If a test shows a normal level, the search moves on to blood sugar, thyroid, kidney function, medicines, alcohol and pressure on a nerve.
Checklist07
What should you bring to the appointment?
A short, honest list helps a clinician more than a long story.
| Bring | Why it helps |
|---|---|
| Every medicine and dose | Metformin and acid reducers are named in the sources |
| Every supplement, including multivitamins | Some already contain B12 or B6 |
| When the symptoms started | Gradual and sudden problems point to different causes |
| Where it happens | Both feet, one hand or one side of the body each mean different things |
| What makes it better or worse | Rest, walking, night time or position can hint at the cause |
| Diet notes | Mention if you eat few or no animal foods |
Write the list down before you go, because appointments are short. If you have a photo of the Flow Nerves bottle, show it, and say plainly that the amounts are not printed on the front.
Timing08
Can a supplement hide a B12 problem?
It can, if you start one before you are tested, and that is why timing matters.
A product that contains some of the nutrients being measured can change a blood result, and a product that eases a symptom for a while can delay a visit. Neither is a reason to avoid all supplements. It is a reason to be tested first when you have symptoms, then to start anything new with your clinician's knowledge. Flow Nerves has no B12 among its six names, so it would not change a B12 result directly, yet we still suggest the order: test, talk, then decide.
FAQ09
Flow Nerves questions people ask
Does Flow Nerves contain vitamin B12?
Not among the six names in the brief. Check your bottle for any other lines.
Can low B12 cause numbness in hands and feet?
Yes. NIH says a shortage can make hands and feet numb or tingly.
Does metformin lower vitamin B12?
A PubMed review says metformin can block B12 absorption and that periodic B12 monitoring is recommended. Keep taking metformin as prescribed.
Should I take B12 with Flow Nerves?
Ask your clinician. A B12 plan depends on a test, and we give no doses.
How is low B12 found?
With a blood test ordered by a clinician. We give no doses and no test targets, because they depend on the person.
Can diet alone cause low B12?
It can, mainly for people who eat few animal foods, but absorption problems and medicines matter too.
What other vitamins affect nerves?
Cleveland Clinic lists copper, B1, B6, B9 and E alongside B12, and NINDS names excess vitamin B6 as a cause. A clinician can check which matter for you.
Who wrote this10
Written and reviewed by
Pages built from the brand files and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is the information site for a USA Authorized Flow Nerves Retailer. It is not the manufacturer. We earn money when you buy through our order links.
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