How to Find Your Vitamin C Optimal Dose

Due to recent world events, our immune health has been in the spotlight, and rightly so! It is well known that Vitamin C can help support your immune system, but how much do you need personally? That depends the level of stress affecting your body: physical stress, emotional stress, and chemical stress. This is because stressors use up antioxidants, including Vitamin C, depleting the supply that is necessary for optimal immune function and more. Humans are one of the few animals that do not make our own Vitamin C. In order to have enough Vitamin C in your system to support immune function, you must first get enough to fulfill the demands of your environment. 

This post will answer your most pressing questions about Vitamin C:

  • How much Vitamin C do I need to take?
  • Can’t I get enough from oranges and other foods?
  • Isn’t food-sourced Vitamin C better for me? 
  • What is the best form to take?Will I get kidney stones if I take too much? 
  • Will my optimal dose change? How will I know if it does?
  • Is Vitamin C just for my immune system during cold season? 

How much Vitamin C do I need to take? Finding your personal Vitamin C Optimal Dose:

Finding your unique optimal dose of Vitamin C requires you to find your “bowel tolerance” for the vitamin. Vitamin C is water soluble, and when we take ‘too much’ our bowels respond by evacuating the excess (ie. diarrhea). Our optimal dose of Vitamin C is slightly below our bowel tolerance. This simple at home experiment can help you find your optimal dose: 

  1. Find a morning in your schedule with no social obligations, where you will be able to stay close to home. Eat and take your supplements as per usual. 
  2. Starting in the morning, take 1000mg of Vitamin C each hour, and stop when you get diarrhea or you feel really gassy —this means you have surpassed bowel tolerance. 
  3. Tally the total amount of vitamin C that you had consumed to reach bowel tolerance. 
  4. Subtract 1000mg from this total. This is your daily total Vitamin C optimal dose. 
  5. Going forward, divide your total optimal dose into 2 or 3 doses throughout the day. 

Optimal Daily Dose = Bowel Tolerance – 1000mg 

Example: If it took 10 000mg to reach bowel tolerance:

    10 000mg  –  1000mg  =  9000mg

 Then, divide this dose through the day  

9000mg/3 = 3000mg, 3x daily


Can I get enough Vitamin C from oranges and other foods?

It takes about 40 oranges to yield 2000mg or Vitamin C, which is still below the bowel tolerance of many modern individuals. Supplementation makes more sense, and is much more cost effective (1). 

Isn’t food-sourced Vitamin C better for me? 

All the body requires is the ascorbate molecule, regardless of its source. The ascorbate produced in a lab from glucose is bio identical to the ascorbate produced in the livers of mammals that do so (1). 

What is the best form of Vitamin C to take?

There is a lot of talk about different ‘superior’ forms of Vitamin C in the alternative health world. All that is required by your body from a Vitamin C supplement is ascorbic acid (1). If ascorbic acid is too tough on your stomach, then calcium ascorbate or magnesium ascorbate from your local nutrition store is just fine. Do not use time release tablets. 

Will I get kidney stones if I take too much?

I will directly quote a research paper on this one 

“Some medical authorities seem desperate to show that Vitamin C causes harm. One recurrent scare story is that vitamin C might cause kidney stones. However, although such warnings pop up regularly, these reports do not demonstrate an increase in the number or size of stones; instead, they rely on vague indicators of improbable risk. This evidence suggests that a high vitamin C intake has no effect on the number of kidney stones, or may even be protective.” (Steve Hickey PhD, Hilary Roberts PhD, Vitamin C Does not Cause Kidney Stones, 2005) 

Will my optimal dose change? How will I know if it does? 

Your optimal dose will change as the amount of stress on your body changes. If you find yourself with higher physical and emotional demands, it may go up. When the opposite happens, your tolerance could lower.  If it does, your body will let you know by ringing the “bowel tolerance” bell and your current dose will cause diarrhea or gas. If the demand for Vitamin C goes up, the signs can be quite subtle. To self assess for increased Vitamin C demand, you can repeat the experiment every few months, or add 1000mg to your total dose daily until you find your new bowel tolerance.  

Is Vitamin C just for my immune system during cold season? 

In addition to direct immune support, Vitamin C plays an active part in the following (1):

  1. Manufacturing collagen (important for skin and bowel healing) 
  2. Strengthening blood vessels
  3. Manufacturing hemoglobin in red blood cells
  4. Secreting adrenal hormones
  5. Acts as an antihistamine
  6. Produces internal anti-cancer agents
  7. Prevents atherosclerosis 
  8. Assists in fat loss 

…and it can only do this ALL if you get enough! 

  1. David Rowland, Nutritional Solutions for 88 Conditions, 201
  2. Steve Hickey PhD, Hilary Roberts PhD, Vitamin C Does not Cause Kidney Stones, 2005 

See medical disclaimer. For customized recommendations on diet, lifestyle and supplements that are best suited to your unique body, book your live blood microscopy appointment or a virtual consultation today!

🍎 🔬 Yours in health, 

Carly Del Ciancio
Thrive Live Blood Microscopy

Thank you for reading!

Carly Del Ciancio is the owner and microscopist at Thrive Live Blood Microscopy. She is passionate about sharing the benefits of natural health, and helping her friends, family and clients THRIVE! Carly offers in-office live blood microscopy services in Kingsville & Essex County, as well as wellness consultations near & far. Find out more about Thrive’s services and variety of available tests here.