Elevated Plasma Vitamin B12 Levels as a Marker for Cancer: A Population-Based Cohort Study (revised 2013)revised: http://jnci.oxfordjournals.org/content/105/23/1799
original: http://jnci.oxfordjournals.org/content/early/2013/11/11/jnci.djt315.long
["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."]
The Journal of the National Cancer institute subsequently published a warning to clinicians who find elevated serum levels (reference range 200–600 pmol/L) that these patients may be at risk of developing certain cancers.
The Danish study consisted of 333,000 persons not on "B12 therapy". Those with existing cancers were excluded.
Arendt et al. note that high plasma Cbl levels are probably not related to normal Vitamin B12 intake because consumption of Cbl containing foods or supplements do not increase plasma Cbl levels substantially. Rather, high Cbl levels may result from some unknown malignant process.
My thoughts: Mega B vits often contain 1,667% or more RDA of B12. There may still be some risk from over-supplementation.
In general certain supplements are thought to promote faster growth of existing malignancies. Among the general population there are those who practice mega dosing for various reasons: increased stamina, growth or prevention.
Malignancies are rarely caught early. In an effort to identify markers, studies such as these survey serum levels and ratios then track subject diagnoses and mortality over time.
original: http://jnci.oxfordjournals.org/content/early/2013/11/11/jnci.djt315.long
["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."]
The Journal of the National Cancer institute subsequently published a warning to clinicians who find elevated serum levels (reference range 200–600 pmol/L) that these patients may be at risk of developing certain cancers.
The Danish study consisted of 333,000 persons not on "B12 therapy". Those with existing cancers were excluded.
Arendt et al. note that high plasma Cbl levels are probably not related to normal Vitamin B12 intake because consumption of Cbl containing foods or supplements do not increase plasma Cbl levels substantially. Rather, high Cbl levels may result from some unknown malignant process.
My thoughts: Mega B vits often contain 1,667% or more RDA of B12. There may still be some risk from over-supplementation.
In general certain supplements are thought to promote faster growth of existing malignancies. Among the general population there are those who practice mega dosing for various reasons: increased stamina, growth or prevention.
Malignancies are rarely caught early. In an effort to identify markers, studies such as these survey serum levels and ratios then track subject diagnoses and mortality over time.
