Vitamin C Flush

Vitamin C  – How to dose to match your bodies needs.


As Naturopath it is common practice to dose vitamin C until bowel tolerance, a nicer way to describe it is the Vitamin C flush. This involves taking as much Vitamin C as your gut can tolerate in order to saturate your cells. Once you hit the point at which you can no longer absorb vitamin C from your gut, you will experience an enema like evacuation, like diarrhoea, from your bowel.

There is some evidence to show that the amount of vitamin C which can be tolerated orally, without producing loose stools, increases in correlation to how unwell you are. (2,4)
Most people reach bowel tolerance at around 10-15g, but in an acute illness like a cold that tolerance can increase up to 50g within 24 hours. A bad cold can increase tolerance to 100g, the flu up to 150g and viral pneumonia to as much as 200g within 24 hours.(4)
Large doses of vitamin C should always be given in divided doses and consultation with your health practitioner is always best.


What you need:

       A buffered Vitamin C powder that includes Calcium ascorbate or potassium ascorbate. Best to avoid the ascorbic acid as can cause irritation in such high dose.

How to do it:

-Choose a day when you are at home or close to a toilet you feel comfortable using.

-Start by taking 1000mg of vitamin C in a glass of water

-Repeat this every hour, on the hour, recording each time you take a dose

-Continue taking 1000mg hourly until you go to the toilet with loose stool – a watery stool. Once this occurs you can stop taking the vitamin C. Take note of how much you took in total before hitting bowel tolerance. i.e.: every hour for 6 hours = 6,000mg.

– Continue to drink water throughout the day, you may notice some continued loose stool.

– The following day take 75% of the total amount in 3 divided doses i.e. 75% of 6,000 = 4,500mg which would be 3 divided doses of 1,500mg.

– Each day reduce the total amount you are taking by 1000mg. i.e. The next day take total of 3,500 in 2-3 divided doses until you are down to 500-1000mg daily.


Who shouldn’t do this? Although vitamin C is a water soluble vitamin and your cant actually overdose I would advise against people with the following conditions to avoid.

       Irritable bowel or inflammatory bowel disease

       Gilbert’s disease


– Preconception, Pregnancy or breast feeding


1.Cathcart RF. Clinical trial of vitamin C. Letter to the editor. Med Tribune 1975. [Link]

2.Cathcart RF. The method of determining proper doses of vitamin C for the treatment of disease by titrating to bowel tolerance. J Orthomolecular Psychiatry 1981;10:125-132. [Full Text]

3.Cathcart RF. Vitamin C: titrating to bowel tolerance, anascorbemia, and acute induced scurvy. Med Hypotheses 1981;7(11):1359-1376. [Full Text]

4.Megascorbate therapies: vitamin C in medicine. The Vitamin C Foundation 1997 [Link]


Leave a comment

Online Program

a Way to Wellness

Transform your health & wellness!
Self Paced Online Program Available Now.

Receive the latest news

Sign up to my