Vitamin B12 Deficiency and Fracture Risk After 50: What the New Study Found

A large new study has put an everyday blood test under a new light: adults over 50 with a low vitamin B12 result went on to have more fractures than similar adults with normal levels. Published on September 30, 2026 in Scientific Reports, the work examines vitamin B12 deficiency and fracture risk in more than 230,000 people. It shows an association, not a cause, but it is a good reason to understand what your own B12 number means. Below, we walk through what the researchers did, what they found, where the evidence stops, and what to ask your doctor.

What the new study found about B12 and fractures

The team used electronic health records from a large international network. They included adults aged 50 and older who had a vitamin B12 blood test between 2016 and 2023. People with deficiency, defined as a result of 199 pg/mL or lower, were paired one to one with people whose B12 was in the normal range of 300 to 900 pg/mL. The pairing relied on a statistical method called propensity score matching, which makes the two groups as alike as possible on age, health conditions, medications and other lab results. That left 115,735 people in each group.

According to published summaries of the study, fractures were recorded in 7.2% of the deficient group and 6.0% of the comparison group. Once follow-up time was taken into account, the fracture hazard was about 33% higher in the deficient group (hazard ratio 1.33, 95% confidence interval 1.29 to 1.38). Looking only at years one to five, it was about 37% higher (1.37, 1.32 to 1.42).

Related outcomes pointed the same way, from about 22% higher for osteoporosis without a fracture to about 50% higher for repeated falls. Borderline and high B12 levels were also linked to more fractures, but more weakly, and the pattern across B12 levels was not a straight line.

A built-in sanity check

The authors also tested two reference conditions. High homocysteine, a marker that rises when B12 is low, showed about 41% higher hazard, as expected. Lipoma, a harmless fatty lump that B12 should have nothing to do with, showed no association. Results like these suggest the method was not simply producing noise.

How to read a B12 result on your lab report

The study grouped results into four bands. Labs and health agencies draw the lines in slightly different places, so use the table as a map rather than a verdict.

Many European labs report B12 in pmol/L instead. As a rough guide, multiply pg/mL by 0.74, so 199 pg/mL is about 147 pmol/L.

Because a single B12 number is an imperfect picture of what your tissues have, the NIH notes that doctors may add methylmalonic acid (MMA) when the result falls in a gray zone, roughly 150 to 399 pg/mL. A high MMA suggests true deficiency. If you want the full picture, our guide explains como ler uma análise ao sangue para a vitamina B12.

Why this is an association, not proof

The authors themselves stress that the findings do not show that B12 deficiency causes or predicts fractures. Several limits matter:

• It is an observational study built on health records, so hidden factors can still explain part of the gap.
• B12 was measured once, at the start, and later supplements or changes were not captured.
• Bone density, vitamin D, calcium, parathyroid hormone, diet, physical activity and steroid use were not fully accounted for.
• Fractures from accidents and fragility fractures could not be reliably separated.
• The deficient group had higher mortality and shorter follow-up, which complicates the comparison.
• Everyone had a B12 test ordered for a clinical reason, so results may not apply to all adults.

The study also does not show that taking B12 lowers fracture risk. Prospective studies are still needed.

Why B12 can run low after 50

Mayo Clinic experts explain that B12 deficiency becomes more common with age, mainly because the body absorbs the vitamin less well. Pernicious anemia, an autoimmune condition, is the most common digestive cause. The NIH adds that atrophic gastritis, a thinning of the stomach lining that lowers stomach acid, affects about 2% of the general population but 8% to 9% of adults aged 65 and older.

Some medicines also play a part. Proton pump inhibitors, H2 blockers and metformin can interfere with absorption or lower blood levels. Importantly, you can have a low B12 without anemia, so a normal blood count does not rule it out. Our article on sintomas e causas da deficiência de vitamina B12 covers the nerve and blood signs in detail, and our guide to os níveis de homocisteína explains the marker that rises alongside it.

Últimos avanços científicos

What is new here is the scale and the design. The study is very large, it compares closely matched groups, and it adds control conditions to check for bias. It does not settle whether low B12 harms bone.

Earlier research is mixed. A 2017 systematic review concluded that the link between B12, bone density and fractures was not well established, partly because studies defined B12 status in different ways. A later follow-up of the B-PROOF randomized trial, in older adults given B12 with folic acid for two to three years, found no overall reduction in fractures. A possible benefit in people with high homocysteine appeared, but it needs confirmation.

What this changes for you: a low B12 result deserves attention for its own sake, because it can affect nerves and blood. This study adds a reason to ask whether bone health and fall risk are also being looked at. It is not a reason to start supplements on your own to protect your bones.

Which results to read together

Doctors rarely look at B12 alone. It helps to review your folate result, since low folate can mask or mimic B12 problems. For the bone side, your doctor may also look at your calcium and bone panel, your 25-OH vitamin D level e your parathyroid hormone (PTH) result.

Quando falar com o seu médico

Bring up your B12 result, or ask for a test, if any of the following applies:

• Tingling, numbness or burning in the hands or feet, or trouble with balance.
• Recent falls, or a fracture after a minor fall.
• Unusual fatigue, pallor, memory changes or low mood.
• Long-term use of metformin, a proton pump inhibitor or an H2 blocker.
• A previous B12 result below about 300 pg/mL that was never followed up.

Only a clinician who knows your history can interpret your results and decide on any treatment.

Glossário

• Rácio de risco: a measure comparing how fast events occur in two groups over time. 1.33 means about 33% higher.
• Propensity score matching: a method that pairs people who look alike on many characteristics to make comparisons fairer.
• Estudo observacional: research that observes what happens to people without assigning a treatment, so it can show links but not prove causes.
• Ácido metilmalónico (AMM): a substance that builds up when B12 is lacking, used to confirm a deficiency.
• Homocisteína: an amino acid that rises when B12, folate or B6 run low.
• Anemia perniciosa: an autoimmune condition that prevents the body from absorbing B12.

FAQ

Does low vitamin B12 cause fractures?

This study cannot say. It found that fractures were more frequent in adults over 50 with low B12, but the authors state that it does not show cause or prediction.

What B12 level is considered deficient?

The study used 199 pg/mL or lower. Most labs treat values below 200 pg/mL as subnormal, and the 200 to 300 pg/mL range is considered low or marginal. Reference ranges vary by lab.

Should I take B12 supplements to protect my bones?

Current evidence does not support that. In a long-term trial follow-up in older adults, B12 with folic acid did not reduce fractures overall. If your level is low, your doctor will decide whether and how to treat it.

Can a normal blood count rule out B12 deficiency?

No. According to Mayo Clinic, not having anemia does not rule out a deficiency, which is why a specific B12 test is used.

Which medicines can lower B12?

Proton pump inhibitors, H2 blockers and metformin are the best known. Do not stop a prescribed medicine without medical advice.

Fontes

• Yang C, et al. Vitamin B12 status and long-term fracture risk in a multicenter propensity score-matched cohort. Scientific Reports, 2026
• NIH Office of Dietary Supplements: Vitamin B12 fact sheet for health professionals
• MedlinePlus: Vitamin B12 level
• Mayo Clinic News Network: Vitamin B-12 deficiency more common with increasing age
• Oliai Araghi S, et al. Long-term effects of folic acid and vitamin B12 supplementation on fracture risk and cardiovascular disease: extended follow-up of the B-PROOF trial. Clinical Nutrition, 2020 (via PubMed)
• Macêdo LLG, et al. Vitamin B12, bone mineral density and fracture risk in adults: a systematic review. Revista da Associação Médica Brasileira, 2017 (via PubMed)

Outros artigos

• Análise ao Sangue de Vitamina B12: Como Interpretar os Seus Resultados
• Vitamina B12 baixa: Sintomas, Causas e Lesões Nervosas
• Níveis de Homocisteína: O Que Significa Realmente um Resultado Elevado
• Análise de Vitamina D no Sangue (25-OH): Como Ler os Seus Resultados
• Vitamin D 5,000 IU: what the research says

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