Why even non-vegetarians can be low on vitamin B12

A routine blood test. A casual follow-up. Then comes the surprise. “Doctor, my B12 is low? But I eat chicken and eggs regularly.” This is a line many physicians now hear more than expected. Vitamin B12 deficiency was once seen mainly in strict vegetarians. Today, even regular meat-eaters are walking out of clinics puzzled by low levels.
The shift is real. And it reveals something important: nutrition is not only about what goes on the plate. It is also about what the body can absorb, store, and use.
As Dr H Guru Prasad, Clinical Director and HOD, Department of General Medicine/Internal Medicine, CARE Hospitals, Banjara hills, Hyderabad, shared in a conversation with TOI Health, “Over the past few years, I’ve seen a steady rise in B12 deficiency among people who eat meat without restriction. That usually leaves them confused, and sometimes frustrated.”
Here is why this is happening, and why it matters.

Vitamin B12 is not a trendy nutrient. It is basic and essential.
It supports nerve function, helps form red blood cells, and plays a role in DNA synthesis. Without it, the body struggles to make healthy blood and maintain nerve integrity.
Dr Guru Prasad explains, “Vitamin B12 is essential for nerve function, red blood cell formation, and DNA synthesis.”
When levels drop, the body does not always send loud warning signs. The effects can be subtle at first, then slowly disruptive.

B12 deficiency rarely announces itself dramatically.
Fatigue is common. But it is not the usual tiredness after a long day. Patients describe it as heaviness, low mood, poor focus, or mental fog. Some report tingling in their hands and feet. Others notice hair fall.
Dr Guru Prasad notes, “Patients describe it as heaviness, poor concentration, irritability, or tingling in the hands and feet.”
Sometimes, the only clue is mild anaemia on a routine blood test. In other cases, numbness is blamed on long desk hours or bad posture. Months can pass before anyone checks B12 levels.
The problem is that nerve damage from prolonged deficiency can become harder to reverse if ignored for too long.

This is the real question. If B12 is found in animal foods, why are meat-eaters deficient?
The answer lies in absorption.
Vitamin B12 needs a healthy stomach lining and a protein called intrinsic factor to be absorbed. If the stomach lining is inflamed or damaged, absorption drops.
Dr Guru Prasad explains, “The answer often has less to do with intake and more to do with absorption.”
Chronic gastritis, long-term acid reflux, and frequent use of antacids can interfere with B12 absorption. Many young adults take over-the-counter acidity medicines for months or years without medical supervision.
“Regular use of certain antacids can interfere with this process,” he says.
Gut health plays a role too. Infections, inflammatory bowel conditions, or previous intestinal surgeries can reduce absorption. Even mild digestive discomfort that is ignored may signal underlying issues.

There is another silent factor: eating habits have changed.
Many professionals eat non-vegetarian food, but irregularly. A weekend chicken meal does not compensate for skipped breakfasts and processed weekday lunches.
Dr Guru Prasad observes that small or inconsistent portions of animal foods may not be enough. Alcohol can further impair nutrient absorption and increase depletion over time.
The body stores vitamin B12 in the liver. But those stores are not infinite. If intake has been borderline for years, deficiency develops gradually. It may take time before symptoms appear.
Dietary guidelines from the National Institute of Nutrition and the Indian Council of Medical Research (ICMR) together state that a regular and well-balanced consumption of foods high in B12 is very much necessary to prevent deficiency.
Global data also shows that B12 deficiency is not rare. The US National Institutes of Health reports that certain groups, including older adults and people with gastrointestinal disorders, are at higher risk.
The takeaway is simple: deficiency is not limited to one diet group.

As people age, stomach acid production can decline. Less acid means poorer B12 release from food.
Older adults are particularly vulnerable. The NIH notes that reduced stomach acid in ageing affects absorption.
Long-term conditions like chronic gastritis and autoimmune disorders can also damage intrinsic factor production. Without intrinsic factor, B12 cannot be absorbed properly, no matter how much meat is consumed.
In such cases, diet alone may not solve the problem.

The frustrating part is how easily B12 deficiency hides.
Dr Guru Prasad shares, “I’ve had patients treated repeatedly for fatigue before someone finally checks their B12 level.”
A simple blood test can offer clarity. When detected early, treatment is usually straightforward. Depending on severity, supplementation may be oral tablets or injectable forms.
“But treatment should also address the underlying cause,” he emphasises. Whether it is excessive antacid use, gut inflammation, or dietary imbalance, the root issue matters.
Ignoring the cause may lead to recurring deficiency.

There is a common belief that youth equals immunity. That belief is misleading.
Dr Guru Prasad advises, “Don’t assume you’re protected just because you eat meat.”
Persistent fatigue, brain fog, unexplained tingling, or low mood deserve attention. They are not always stress or burnout. Nutrition is not just about intake. It is about absorption and long-term balance.
As Hippocrates once said, “Let food be thy medicine.” But medicine only works if the body can use it.
Paying attention to subtle symptoms and seeking timely medical advice can prevent months of silent discomfort.

Medical experts consulted
This article includes expert inputs shared with TOI Health by:
​Dr H Guru Prasad, Clinical Director and HOD, Department of General Medicine/Internal Medicine, CARE Hospitals, Banjara hills, Hyderabad
Inputs were used to explain why even non-vegetarians can develop vitamin B12 deficiency and why one should consult a doctor before starting supplements or self-treating.