Vitamin B12
B12 Deficiency and Tingling: Who Should Get Tested?
Low vitamin B12 can cause numbness and tingling in the hands and feet, sometimes before any anemia shows up. Older adults, people on metformin and people who take acid reducers are most likely to run low. If you have tingling, ask your doctor for a B12 blood test before buying any supplement, including Nerve Savior.
Written by the Nerve Savior editorial teamUpdated · 8 min read
The link
Can low vitamin B12 cause tingling and numbness?
Yes. A shortage of vitamin B12 can cause numbness and tingling in the hands and feet, and it can do so even when blood counts look normal (NIH ODS, Vitamin B12).
Federal neurology experts name B12 deficiency as one of the best-known vitamin causes of peripheral neuropathy (NINDS, Peripheral Neuropathy). That makes it worth checking early, because it is one of the causes a doctor can test for and treat.
Adults need only 2.4 mcg of B12 a day, a little more in pregnancy and while nursing (NIH ODS, Vitamin B12). Some common medicines can lower B12 or get in the way of absorbing it (NIH ODS, Vitamin B12).
Tingling has many causes. A blood test tells you whether B12 is one of them. Without it, you cannot know whether a supplement is aimed at the right problem.
Risk groups
Who should get tested for B12 deficiency?
These groups have the strongest reasons to ask.
| Who | Why they are at risk | What to ask |
|---|---|---|
| Older adults | Deficiency affects 3% to 43% of older adults living at home, depending on how it is defined | Whether a B12 test belongs in routine bloodwork |
| People taking metformin | Metformin may significantly lower blood B12 levels | How often to check B12 while on metformin |
| People on acid reducers | Proton pump inhibitors and H2 blockers can interfere with absorbing B12 from food | Whether long-term use calls for a test |
| Anyone with new tingling or numbness | Low B12 is one of several causes, and it can appear without anemia | A B12 test along with blood sugar and other checks |
| People with diabetes | Diabetes is the most common cause of neuropathy, and many also take metformin | Which test explains the symptoms |
Several of these overlap. An older adult with diabetes who takes metformin and an acid reducer has three reasons at once. The metformin and B12 article covers that group in detail.
The bigger picture
What else causes tingling besides low B12?
Many things do, which is why a doctor's visit matters more than any single vitamin. Mayo Clinic lists diabetes and metabolic syndrome as the most common causes (Mayo Clinic, Peripheral Neuropathy Symptoms). It also lists:
- Heavy alcohol use
- Low levels of vitamins B1 and B6, as well as B12
- Autoimmune disease and some infections
- Kidney, liver or thyroid disease
- Toxins and certain medicines, such as chemotherapy
Up to half of long-term heavy drinkers develop alcohol-related nerve damage (MedlinePlus, Alcoholic Neuropathy). Too much B6 from supplements can also cause tingling (NIH ODS, Vitamin B6), a point covered in vitamin B6 and nerves. A good workup looks at several of these together.
Quick check
Should you get a B12 test before trying a nerve supplement?
Five questions. The last one is the B12 question. Your answers stay on your screen.
If the answer to the last question is no, start there. The test is simple, and the result shapes everything that follows.
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Does a B12 supplement like Nerve Savior replace a test?
No. A supplement cannot tell you whether you are low, and the cause of your tingling may not be B12 at all. Nerve Savior contains B12 as "Cyanocobalamin 1%," ninth in a 600 mg blend, with no amount printed. By its place in the list, it could hold up to about 667 mcg of B12 per serving.
B12 has no upper limit, because high doses are generally considered safe (NIH ODS, Vitamin B12). The bigger issue is the rest of the formula. Most of its other ingredients were studied for memory or eyes, and its B6 amount is hidden.
If a test shows you are low, your doctor will suggest a dose and a form that fit the cause. That plan should come from the test, not from a nerve-support label. See the vitamin B12 ingredient profile for more.
Do not wait
When is tingling a reason to see a doctor right away?
Mayo Clinic advises seeing a doctor right away for tingling, weakness or pain in the hands or feet (Mayo Clinic, Peripheral Neuropathy Symptoms). Sudden numbness or weakness on one side of the body is an emergency: call 911.
CDC also says people with diabetes should see a doctor or podiatrist right away for a foot blister, sore or ulcer (CDC, Diabetes and Your Feet).
Your appointment
What should you bring to a B12 test appointment?
A little preparation makes a short visit much more useful.
- A week before
Write down where you feel tingling, when it started and whether it is spreading.
- The day before
Gather every medicine and supplement bottle, including acid reducers, metformin and any B vitamins.
- At the visit
Ask whether B12, blood sugar and other tests fit your symptoms, and when results will come back.
- After the results
Ask what the numbers mean, what treatment is suggested and when to recheck.
More on symptoms and causes is in the tingling and numbness guide.
FAQ
B12 deficiency and tingling FAQ
Can low B12 cause tingling in hands and feet?
Yes. Vitamin B12 deficiency can cause numbness and tingling in the hands and feet, and it can happen even when you are not anemic. It is one of the best-known vitamin causes of nerve damage, and one a simple blood test can check, so ask your doctor about it.
Who is most at risk for vitamin B12 deficiency?
Older adults, people who take metformin and people on acid reducers such as proton pump inhibitors or H2 blockers are most at risk. Estimates put deficiency at 3% to 43% of older adults living at home, depending on how it is defined. If you are in one of these groups and have tingling, ask about a test.
How much vitamin B12 do adults need a day?
Adults 19 and older need 2.4 mcg of vitamin B12 a day, rising to 2.6 mcg in pregnancy and 2.8 mcg while breastfeeding. There is no upper limit, because B12 is generally considered safe even in high doses. Need and absorption are different things, though.
Should I take B12 before getting tested?
It is better to talk to your doctor and get tested first. A test shows whether you are actually low and helps your doctor pick the right dose and form. Tingling has many causes, and starting a supplement first can leave the real cause unchecked for longer.
Is the B12 in Nerve Savior enough to fix a deficiency?
No one can say, because the label prints no amount. B12 is ninth in a 600 mg blend as a 1% mix, so a serving holds at most about 667 mcg. Your doctor should set a dose based on your test result and what caused the low level.
What tests check for nerve-related tingling?
Your doctor chooses tests based on your history, but a B12 level and a blood sugar check are common starting points. Others may look at thyroid, kidney or liver function. Bring a list of your medicines and supplements, since some drugs lower B12 and too much B6 also causes tingling.
Can diabetes medicine lower my B12 and cause tingling?
It can. Metformin may significantly lower blood levels of vitamin B12, according to the NIH Office of Dietary Supplements, and low B12 can cause tingling. Not everyone on it becomes deficient, but it is a good reason to ask your doctor about testing. Keep taking metformin as prescribed while you ask.
Who wrote this
Written and reviewed by
Plain-language pages built from the label, the sales listing and linked public health sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by Thenervesavior, a U.S. stocking partner, not by the manufacturer or the distributor named on the label. We earn money when you buy through our order links.
Keep reading
More about Nerve Savior
Vitamin B12
The B12 in Nerve Savior: the most a serving could hold, who runs low, and why testing comes first.
Read more
Tingling and numbness guide
Common causes of tingling and numbness, the red flags, what a doctor checks, and daily foot care.
Read moreMetformin and B12
Metformin can lower B12, and low B12 can mimic diabetic nerve symptoms. What to ask, and what not to change.
Read moreU.S. stocking partner for Nerve Savior
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