Orthopedic claims B12 tablet gives ‘false positive results’ compared to injection; internal medicine expert says ‘not necessarily true’

This mismatch is more common in:

– vegetarians and vegans
– those with poor gut health or malabsorption
– people on long-term acidity medicines (PPIs, H2 blockers)
– individuals taking metformin
– adults over 40, where absorption naturally declines

If the routine test can miss a deficiency, which tests detect the real B12 status?

More sensitive markers include:
– Methylmalonic acid (MMA)
– Homocysteine

These markers rise when B12-dependent enzymes malfunction.
So if MMA or homocysteine is high despite a normal serum B12, it strongly suggests tissue-level deficiency.

You may need these tests if you have ongoing symptoms or risk factors, even with a normal report.

Are B12 injections really better than tablets?

They can be, depending on the person, said Dr Ugalmugle. Tablets rely on gut absorption. “If someone has gastritis, IBS, age-related absorption decline, long-term acid suppression, metformin use, or anaemia, tablets may not raise levels effectively,” described Dr Ugalmugle.

Here’s what you should consider (Photo: Getty Images/Thinkstock)

Injections bypass the gut and enter the bloodstream directly. “They correct deficiency faster, stabilise levels better, and are more predictable,” said Dr Ugalmugle.

This does not mean injections are “stronger.” They’re just more reliable when absorption is impaired.

Who genuinely needs injections, and who can manage with tablets?

Injections are preferred for:
– vegetarians/vegans with very low intake
– people over 40
– those on PPIs, H2 blockers, or metformin
– anyone with neurological symptoms (numbness, tingling, memory issues)
– patients with gastric disorders or post-surgery malabsorption

Tablets are suitable for:
– mild deficiency
– individuals with good gut health
– people with no interfering medications
– dietary insufficiency without symptoms

Treatment is always personalised.

Can lifestyle habits prevent B12 deficiency in the long term?

Partially, affirmed Dr Uglamugle. “Supporting gut health, reducing unnecessary acidity medicines, managing stress, and eating fortified foods or adding eggs/dairy (if allowed) can help maintain levels,” said Dr Ugalmugle.

But strict vegetarians, older adults, and those with chronic gut issues usually need periodic supplementation, even with good habits, added Dr Ugalmugle.

DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.