It is important to note that this concern is entirely theoretical -- no oncological adverse effects have been reported in the limited preclinical studies -- but the biological plausibility is high enough to warrant serious consideration
In contrast, there is some evidence of an enhancement of the maximum absorption via intrinsic factor, by up to a factor of 2, when the vitamin B12 is accompanied by food, but this is not consistently observed and probably only applies when the food quantity and vitamin B12 dose are sufficient to slow the passage of the vitamin B12 through the small intestine enough (about three hours or more) to allow each intrinsic factor receptor to absorb two molecules of vitamin B12 from the oral dose rather than one
If an athlete cant find the brand name of their medication on Global DRO, they can also search the active ingredients listed on the medication label, which is often necessary in the case of cold, flu, and other such over-the-counter medications
But, if they dont or get worse, its important to talk to a doctor