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Vitamin B12 and Metformin: Why Low B12 Can Mean Numb Feet
Vitamin B12 and metformin are linked because metformin may reduce how much B12 your body absorbs. A B12 shortage can show up as numb, tingling hands and feet. If you take metformin and your feet feel odd, ask your clinician for a B12 blood test.
Written by the Nervecept label deskUpdated · 4 min read
Can metformin lower vitamin B12?
Yes. The NIH Office of Dietary Supplements says metformin may reduce B12 absorption and can significantly lower the B12 level in the blood (NIH ODS, Vitamin B12).
Metformin is a common diabetes medicine, so many people take it for years. The same source names other drugs that can lead to a shortage, and one group of people who absorb B12 less well.
| Factor | What the source says |
|---|---|
| Metformin | May reduce absorption and lower blood B12 |
| Acid reducers | Long-term PPIs and H2 blockers can lead to deficiency |
| Older age | Older adults absorb B12 less well |
Do not stop or change metformin because of this. Low B12 is a reason to talk to your clinician, not to skip a dose.
Does low B12 cause numbness and tingling?
It can. Deficiency can cause numbness and tingling in the hands and feet, sometimes without anemia (NIH ODS, Vitamin B12).
That last point matters. A normal blood count does not rule out a B12 problem. NINDS also lists B12 deficiency among the causes of peripheral neuropathy (NINDS, Peripheral Neuropathy).
Diabetes itself is the leading cause of nerve damage, so numb feet in a person on metformin have at least two possible causes. Only tests can sort them out.
Should you ask for a B12 test?
Yes, if you take metformin and have numb, tingling or burning feet. Ask your clinician whether your B12 level has been checked.
Write down your symptoms
Note where it happens, when it started and whether it is worse at night.
List what you take
Include metformin, acid reducers and every supplement.
Ask about a B12 blood test
Ask what the result means for you and what to do next.
The RDA for adults is 2.4 mcg a day, and no upper limit has been set (NIH ODS, Vitamin B12). Do not guess at a dose. Let the result guide the plan.
Does Nervecept contain vitamin B12?
No. The Nervecept label lists eight lines, and none is vitamin B12. It also has no B6, folate or alpha-lipoic acid.
The biggest line is glucosamine sulfate at 500 mg, a joint ingredient made from crayfish shells. The capsule contains shellfish, so skip it with a shellfish allergy.
So Nervecept cannot fix a B12 shortage, and it does not treat neuropathy. See all lines on the ingredients page, or read the nerve vitamins guide.
- 1Glucosamine Sulfate500 mg · 71.5% of the actives · Joint compounds
- 2Indian Frankincense (Boswellia serrata)(herb)67 mg · 9.6% of the actives · Plant extracts
- 3Chondroitin Sulfate50 mg · 7.2% of the actives · Joint compounds
- 4Turmeric (Curcuma longa)(root)50 mg · 7.2% of the actives · Plant extracts
- 5Quercetin (Sophora japonica)(bud)8 mg · 1.1% of the actives · Plant extracts
- 6Methionine8 mg · 1.1% of the actives · Amino acid
- 7Methylsulfonylmethane (MSM)8 mg · 1.1% of the actives · Sulfur compound
- 8Bromelain (Ananas comosus)(stem)8 mg · 1.1% of the actives · Plant extracts
From the Supplement Facts panel on the label: every line has an exact amount, and no line has a Daily Value. The capsule shell (hypromellose) and rice flour are not counted. The glucosamine is made from shellfish (crayfish).
FAQ01
Nervecept questions people ask
How long does metformin take to lower B12?
The sources used here do not give a timeline. The NIH says metformin may lower B12, so ask your clinician how often to check your level.
Can I just take a B12 pill on metformin?
Ask first. A test shows whether you are low, and your clinician can pick the form and amount. Nervecept is not a substitute because it contains no B12.
Is numbness from metformin permanent?
The sources used here do not say. Low B12 is one possible cause of numb feet, and so is diabetes. Ask your clinician to look for the cause.
Who wrote this02
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by a Nervecept licensed U.S. outlet, not by the manufacturer or the distributor. We earn money when you buy through our order links.
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