The Claim

Serum vitamin B12 concentrations between 400–600 pmol/L are associated with a 34% higher risk of all-cause mortality compared to serum vitamin B12 concentrations below 400 pmol/L, indicating a graded increase in risk even within the range below the commonly recognized threshold of >600 pmol/L.

Source: The origin of vitamin B12 levels and risk of all-cause, cardiovascular and cancer specific mortality: A systematic review and dose-response meta-analysis.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
48score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

People with vitamin B12 levels between 400 and 600 units in their blood are 34% more likely to die from any cause than people with lower levels—even though those levels are still considered normal by doctors.

See the scientific wording

Serum vitamin B12 concentrations between 400–600 pmol/L are associated with a 34% higher risk of all-cause mortality compared to lower levels, indicating a graded risk increase even below the >600 pmol/L threshold.

What the research says

1 study
  1. Study: The origin of vitamin B12 levels and risk of all-cause, cardiovascular and cancer specific mortality: A systematic review and dose-response meta-analysis.

    This study found that people with B12 levels between 400 and 600 pmol/L had a 34% higher chance of dying from any cause compared to those with lower levels, which is exactly what the claim says.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.