Vitamin C

From James Dinicolantonio

Blood levels of vitamin C in the 70-80uMol level have been associated with a lower risk for numerous chronic diseases. Studies have shown that for the majority of people to reach these levels in the blood around 500 mg of vitamin C is needed per day.

However, at vitamin C levels above 70uMol, there can be drops below this level unless another 500 mg is given around 4 hours later. Basically, it appears that in order to continually maintain such levels 500mg may need to be consumed around 4 times per day.


Some vitamin C experts have suggested that taking vitamin C every 2-4 hours is optimal and would match patterns that would occur in animals who can’t synthesize vitamin C like humans but get vitamin C continuously throughout the day during foraging.

Some experts believe around 6-9 grams of vitamin C per day (divided into at least 4 smaller doses per day) is optimal based on maintaining continuous high blood levels of vitamin C.

Additionally, there appears to be no real evidence that higher doses of vitamin C actually causes kidney stones (and some evidence that vitamin C may actually reduce kidney stones as ascorbic acid can bind calcium potentially preventing calcium oxalate stone formation). The upper limit of 2 grams of vitamin C per day was set to due to some people getting diarrhea at that level. That would be like someone saying don’t eat more than 2 prunes per day because you could get diarrhea. That doesn’t seem to be a very good justification on capping the dose of vitamin C to just 2 grams per day when animals that make vitamin C produce well over 2 grams per day when matched for human size (and if stressed their production of vitamin C can go up exponentially making much more than 2 grams per day).

This is not medical advice.

What is the right dose?