Researchers in Denmark have published findings in the Journal of the National Cancer Institute suggesting that higher than normal levels of Vitamin B12 may indicate a person is at risk of developing certain cancers.
Download the full text and data published in the Journal of the National Cancer Institute here
A team of scientists led by Johan Arendt, from Aarhus University Hospital in Denmark studied the records of more than 300,000 patients and found that chances of having cancer rose with higher blood levels of vitamin B12, also known as cobalamin (Cbl).
The overall risk of cancer increased especially during the first year after having a blood test and in those patients with levels of 800 picomoles per litre (pmol/L) or more. Researchers excluded patients who had a cancer diagnosis before the date of the blood test, and those who were receiving vitamin B therapy.
“High plasma Cbl levels increased the risk of subsequently diagnosed cancer, mostly within the first year of follow-up.”
See the Abstract below or download the full text of their article published in the Journal of the National Cancer Institute here
A substantial proportion of patients referred for plasma vitamin B12 (cobalamin [Cbl]) measurement present with high Cbl levels, which have been reported in patients with different cancer types. However, the cancer risk among patients with newly diagnosed high Cbl levels has not been adequately examined.
We conducted this cohort study using population-based Danish medical registries. Patients referred for Cbl measurement with levels greater than the lower reference limit (≥200 pmol/L) were identified from the population of Northern Denmark during the period of 1998 to 2009 using a database of laboratory test results covering the entire population. Data on cancer incidence (follow-up 1998–2010), Cbl treatment, and prior diagnoses were obtained from medical registries. Patients receiving Cbl treatment were excluded. Cancer risks were calculated as standardized incidence ratios (SIRs) with 95% confidence intervals (CIs), stratified by plasma Cbl levels. All statistical tests were two-sided.
We identified 333 667 persons without prevalent cancer and not receiving Cbl treatment. Six percent had Cbl levels greater than the upper reference limit (≥601 pmol/L). Cancer risk increased with higher Cbl levels and was highest during the first year of follow-up (Cbl 601–800 pmol/L: SIR = 3.44, 95% CI = 3.14 to 3.76; Cbl >800 pmol/L: SIR = 6.27, 95% CI = 5.70 to 6.88; both P < .001). The risks were particularly elevated for hematological and smoking- and alcohol-related cancers for persons with high Cbl levels.
High Cbl levels were associated with the risk of subsequently diagnosed cancer, mostly within the first year of follow-up. This may have clinical implications for the interpretation of high Cbl levels.