Symptoms of Low B12
- Tiredness and breathlessness on climbing stairs
- Tingling, numbness or burning in the hands and feet
- Poor balance, especially in the dark
- Memory problems, low mood or irritability
- A sore, red tongue or mouth ulcers
- Pale or slightly yellowish skin
Who Is at Risk?
- Vegetarians and vegans, since B12 comes mainly from animal foods
- People taking metformin for diabetes for several years
- People on acidity medicines (like pantoprazole or omeprazole) for a long time
- Older adults, who absorb B12 less well
- People with stomach or bowel conditions, or after stomach surgery
Testing
A serum B12 level along with a complete blood count usually answers the question. Sometimes the B12 level is borderline, and further tests or a trial of treatment are needed. Iron, folate, thyroid and vitamin D are often checked at the same time, because they cause similar symptoms. Thyroid tests are often done alongside; see thyroid doctor in Panchkula.
Food Sources of Vitamin B12
B12 comes almost entirely from animal foods. If you eat them, these are good sources:
- Eggs
- Fish and chicken
- Milk, curd, paneer and cheese
- Fortified breakfast cereals and plant milks
Dal, vegetables and fruits don't contain B12, however healthy they are. That is why many vegetarians need a supplement, even with a good diet.
B12 and Diabetes
Burning or tingling feet in someone with diabetes is often blamed on high sugar, but low B12 can cause exactly the same symptoms, especially in people who have taken metformin for years. It is a simple blood test and an easy fix, so it is worth checking before assuming the nerve damage is from diabetes alone. More on diabetes treatment in Panchkula.
Treatment
Treatment depends on how low the level is and why. Mild deficiency often responds to tablets. Severe deficiency, or deficiency caused by poor absorption, is usually treated with a short course of injections followed by maintenance doses. If tiredness doesn't improve, see a doctor for weakness and fatigue.
Energy often improves within a few weeks. Nerve symptoms like tingling take longer and improve best when treatment is started early. That is a good reason not to put off testing.
Why Low B12 Gets Missed
The symptoms build up slowly over months or years, so people get used to them. Tingling is blamed on age or diabetes, poor memory on stress, and tiredness on work.
A routine blood count can look normal in the early stages even when B12 is already low, because anaemia shows up later. That is why a direct B12 test is worth asking for if you have nerve symptoms or fall into one of the high-risk groups.
B12 in Older Adults
With age, the stomach makes less acid and B12 from food is absorbed less well. Older adults are also more likely to be on metformin or acidity medicines.
Low B12 in older people can show up as unsteady walking, falls, low mood or memory problems that look like early dementia. It is one of the first tests worth doing when an elderly parent becomes more forgetful or unsteady, because it is treatable.
How Long Treatment Lasts
If the cause is diet, levels usually stay normal with a regular supplement and more B12-rich foods. If the cause is poor absorption, for example after stomach surgery or due to a condition called pernicious anaemia, injections are often needed every few months for life.
Your doctor will repeat the B12 test after a few months to check it has come up. Extra B12 from supplements is rarely harmful, but there is no benefit in taking high doses once your level is normal.
B12, Iron and Folate: Not the Same Thing
Low B12, low iron and low folate can all cause tiredness and anaemia, but they are treated differently. Iron deficiency is the most common cause of anaemia in women, often linked to heavy periods. Folate deficiency is seen with poor diet and in pregnancy. B12 deficiency also affects the nerves, which iron and folate deficiency do not.
Many people have more than one deficiency at the same time. Taking a random multivitamin may not correct any of them properly, so it is better to test first and treat what is actually low.
B12 During Pregnancy and Breastfeeding
Pregnant and breastfeeding women who are vegetarian have a higher chance of low B12, which can affect the baby's development. Many doctors now check B12 along with iron and folate in pregnancy. Supplements are safe, but the dose should be guided by your gynaecologist or physician. Mention your diet clearly at the first antenatal visit.
Frequently Asked Questions
What is a normal vitamin B12 level?
Most labs consider above about 200 to 250 pg/mL normal. Levels below 200 are low, and borderline levels may need more tests.
Can vegetarians get enough B12?
Milk, curd and paneer give some B12, but many vegetarians still fall short. Fortified foods or supplements are often needed.
Are B12 injections better than tablets?
For severe deficiency or poor absorption, yes. For mild deficiency, tablets often work well.
Does metformin cause B12 deficiency?
Long-term use can lower B12. A yearly B12 test is a good idea if you take metformin.
How long does B12 take to work?
Tiredness often improves in two to four weeks. Nerve symptoms can take several months.
Medically reviewed by Dr. Ranjana Bhatt, MBBS, DNB (General Medicine), Associate Director, Internal Medicine, Paras Health Panchkula.