Vitamin B12 deficiency: What it can do to your heart, stomach & nervous system if ignored

Vitamin B12, also known as cobalamin, is one of those nutrients that the body cannot make on its own, yet it plays a role so critical that life without it simply does not function. Found mainly in animal-based foods, or in supplements for those who avoid them, B12 is essential for making DNA, producing red blood cells, and keeping the nervous system healthy. Without it, the body slowly begins to falter.

How Deficiency Shows Up

B12 shortage creeps in quietly. The first signs usually resemble anaemia: tiredness, weakness, pale skin, dizziness, and breathlessness. But if left untreated, the problems go deeper. The nerves begin to suffer, leading to tingling or numbness in the hands and feet, muscle weakness, or difficulty walking. The brain, too, starts to feel the effects, with memory lapses, confusion, mood changes, depression, or irritability becoming common. Some people notice a painful red tongue, loss of appetite, weight loss, or digestive issues like diarrhoea.

The Risks If Ignored

What begins as a vitamin shortage can turn into long-term damage:

• Nerve injury: Prolonged lack of B12 can permanently harm the spinal cord and nerves, causing lasting numbness or even paralysis.
• Heart strain: Severe anaemia forces the heart to overwork, raising risks of heart failure.
• Cognitive decline: Low B12 has been linked to dementia-like symptoms, some of which are reversible if treated early.
• Stroke and heart attack: Deficiency raises homocysteine levels, which is a known risk factor for vascular disease.
• Reproductive and pregnancy issues: Infertility, miscarriage, or birth defects can be triggered by long-term lack of B12.
• Stomach cancer risk: Those with pernicious anaemia, an autoimmune cause of B12 deficiency, face higher chances of developing stomach cancer.

Who Needs to Be Most Careful

Certain groups are more prone to falling short on B12:

• Older adults – absorption declines naturally with age.
• Vegans and vegetarians – since animal foods are the main natural source.
• Those with gut issues – like Crohn’s disease, coeliac disease, or post-bariatric surgery.
• Patients on long-term medication – especially metformin for diabetes or acid-reducing drugs.
• Others – such as heavy drinkers, people with HIV/AIDS, or those with very poor diets.

What the Research Shows

Modern studies continue to uncover the hidden impact of this deficiency. Brain imaging has revealed that even people with “low-normal” B12 levels show more brain changes and slower thinking speeds. Reviews confirm that deficiency is strongly linked to memory loss, neuropathy, and stroke risk. By the age of 75, experts say as many as 40% of people are absorbing less B12 than they need, leaving them vulnerable to silent neurological decline.

Vitamin B12 deficiency is often under-diagnosed, yet it carries real risks, from fatigue and forgetfulness to irreversible nerve damage and dementia. The good news is that it’s usually easy to detect with a simple blood test and, once found, easy to treat with supplements or injections. The key is catching it early, before the damage is done.

In short: this small vitamin packs a mighty punch, and ignoring it could be far costlier than you think.

FAQs
1. What is Vitamin B12 and why do we need it?
Vitamin B12 (cobalamin) is a water-soluble vitamin that helps make red blood cells, keeps nerves healthy, and supports brain function. The body cannot make it, so we must get it from food or supplements.

2. Which foods are rich in Vitamin B12?
Vitamin B12 is mainly found in animal-based foods such as meat, fish, eggs, dairy, and shellfish. Plant-based eaters can get it from fortified foods like cereals, plant milks, or nutritional yeast.

3. Can vegetarians and vegans get enough B12?
It’s difficult for vegetarians and vegans to get enough B12 from diet alone. They may need fortified foods or B12 supplements to avoid deficiency.

4. What are the early signs of Vitamin B12 deficiency?
Early signs include fatigue, weakness, pale skin, dizziness, and shortness of breath due to low red blood cells.

5. What happens if B12 deficiency is not treated?
If left untreated, it can cause nerve damage, memory problems, mood changes, infertility, and even increase the risk of heart disease or stroke.

6. Who is most at risk of Vitamin B12 deficiency?
Older adults, vegans, people with stomach or gut issues, those who’ve had bariatric surgery, and people taking certain medicines like metformin or acid-reducing drugs are at higher risk.

7. How is Vitamin B12 deficiency diagnosed?
Doctors usually check B12 levels with a blood test. Sometimes additional tests for homocysteine or methylmalonic acid are done to confirm.

8. How can Vitamin B12 deficiency be treated?
It can be treated with supplements in tablets, sprays, or injections, depending on how severe the deficiency is and whether the body can absorb B12 properly.

9. Can too much Vitamin B12 be harmful?
There’s no evidence that high intakes from food or supplements are harmful for healthy people, as excess B12 is usually flushed out in urine.

10. Does Vitamin B12 help with energy levels?
Yes. Because it helps produce red blood cells and supports metabolism, adequate B12 can improve energy and reduce tiredness. However, it only helps if you are deficient.