How Much Vitamin C Should I Take?
There are loads of benefits to having sufficient Vitamin C levels in your body. Whether you're getting your Vitamin C through your food, tablet, powder, or any other form, it can be tricky to understand just how much Vitamin C your body will utilize. Have you ever wondered how much Vitamin C your body wants?
Another popular question many of you ask is "Is too much Vitamin C a bad thing?" If you're looking for that answer, check out this blog post: An Orange a Day Probably WON'T keep the Doctor Away.
How Much Vitamin C Should I Be Taking?
Vitamin C mobilizes your immune system cells to look for and destroy foreign attackers. When your body's immune system is needed to fight off something like a flu, cold, or recovering from an injury, it needs Vitamin C to function quickly and effectively.
Vitamin C, also called ascorbic acid, is a water-soluble nutrient. It supports collagen production, antioxidant defenses, immune function, iron absorption and normal wound healing.
Because your body does not store large quantities of vitamin C, excess amounts are generally eliminated. However, when more vitamin C stays in your intestines than can be absorbed, it draws water into the bowel. This can cause rumbling, gas, urgency, cramping or loose stools.
The term “bowel tolerance” was popularized by physician Robert Cathcart in the 1980s. He described taking divided doses of vitamin C until reaching an amount just below the dose that caused diarrhea. His therapeutic theories were published and highlighted in the chart below.
The following list highlights the appropriate amount of Vitamin C you should take when suffering with ailments such as the flu, cold, food allergies, and more. The information for this list was generated by a study done by Dr. Robert F. Cathcart, "How to Determine a Therapeutic Dose of Vitamin C."
Recommended Vitamin C Dosage
- Flu: Take at least 100g to 150g or more of Vitamin C in a 24-hour period divided into 8-20 doses.
- Recovery (From Injury or Surgery): Take at least 25g or up to 150g of Vitamin C in a 24-hour period, divided into 8-20 doses.
- Severe Cold: Take at least 60g or up to 100g of Vitamin C in a 24-hour period, divided into 8-15 doses.
- Mild Cold: Take at least 30g or up to 60g of Vitamin C in a 24-hour period, divided into 6-10 doses.
- Seasonal Allergies (Hay Fever, Asthma): Take at least 15g or up to 50g of Vitamin C in a 24-hour period, divided into 4-8 doses.
- Food Allergies: Take at least .05g or up to 50g of Vitamin C in a 24-hour period, divided into 4-8 doses.
- Anxiety and Stress: Take at least 15g or up to 25g of Vitamin C in a 24-hour period, divided into 4-6 doses.
- Healthy Maintenance: Take at least 4g or up to 15g of Vitamin C in a 24-hour period, divided into 4-6 doses.
I hope this post can act as a benchmark for anyone interested in optimizing the amount of Vitamin C for any circumstance.
What Is Vitamin C Bowel Tolerance?
There is a difference between what your body needs and what it can use for optimal health. Vitamin C is water soluble, so that means your body will dump what it can’t use. There is no risk of toxicity and you can find your best dose by using a bowel tolerance test at home. This is not a medical test, but a DIY home experiment to identify the amount of vitamin C your digestive system can absorb.
The basic idea is simple: You gradually increase oral vitamin C until your digestive system tells you that you have reached your limit. Once your stool becomes noticeably loose, you reduce the amount to a more comfortable level.
Why Is Bowel Tolerance Different for Everyone?
One person may develop loose stools after 500 milligrams, while another may tolerate 8,000 milligrams. Your response may also change from day to day.
Factors that may affect tolerance include:
- The form of vitamin C
- Taken with or without food
- How large each individual dose is
- Your normal bowel habits
- Digestive conditions or sensitivities
- Medications and other supplements
- Hydration and dietary intake
This is why comparing your dose with someone else’s is rarely helpful. The goal is not to take the largest possible amount. The goal is to learn how your own digestive system responds and if large amounts of vitamin C affect any specific symptoms you are experiencing.
How to Do a DIY Vitamin C Bowel-Tolerance Experiment
The traditional bowel-tolerance method can involve very large quantities of vitamin C. I do not recommend intentionally producing severe diarrhea, especially if you are already prone to diarrhea or have IBS or POTS.
Step 1: Choose the Right Day
Pick a day when you will be at home and close to a bathroom. Do not do this experiment before traveling, working a long shift, or attending an important event.
Eat normally and maintain your regular fluid intake. Do not combine the experiment with fasting, laxatives, a cleanse, or other supplements that could affect your bowel movements.
Step 2: Choose a Powdered Vitamin C
Use a powdered vitamin C supplement because it is easy to titrate up on the dose in small increments.
I recommend a buffered vitamin C powder such as calcium ascorbate or a blend of mineral ascorbates. I use this one because it is mineral ascorbates, doesn’t have any sugar, and is easy to measure.
Although I like Liposomal vitamin C, now is not the time to experiment with it. Liposomal vitamin C is absorbed more slowly than powdered vitamin C and it will be difficult to determine your bowel tolerance dose. Here is my blog outlining the differences between liposomal and powdered vitamin C and when you would want to use them.
Avoid any combination formulas that have other nutrients besides vitamin C. Stick with buffered vitamin C only.
I do like combination formulas, but they are not for use to establish bowel tolerance. Sufficient C is my favorite vitamin C drink mix. Here is my blog about why to choose Sufficient C over name brand vitamin C drink mixes like Emergen-C and other formulas. The punchline is that those big brand formulas are filled with sugar and non-absorbable forms of vitamins and minerals.
Step 3: Begin With 250 to 500 Milligrams
Take 250 to 500 milligrams of vitamin C with food and a full glass of water. Write down the time and amount.
Starting low is especially important if you are not accustomed to vitamin C supplements or tend to have a sensitive digestive system.
Step 4: Repeat the Dose Gradually
If your digestive system feels calm, not gassy or cramping, after one hour, take another 250-500 milligrams.
Continue spacing the doses throughout the day while keeping track of your running total. Divided doses are preferable to taking the entire amount at once. A large single dose may cause stomach upset when a smaller amount taken throughout the day would be tolerated.
Step 5: Watch for Your Digestive Signal
Stop increasing the dose at the first clear sign of:
- An unusually loose or unformed stool
- Abdominal rumbling
- Urgency
- Cramping
- Nausea or uncomfortable bloating
You do not need to produce watery diarrhea. The first meaningful change in your digestion is enough information.
For example, suppose you took 500 milligrams at breakfast, 500 milligrams around 10am and another 500 milligrams right before lunch. If the third dose caused loose stool, your bowel-tolerance threshold for that day was approximately 1000 milligrams.
Step 6: Reduce the Amount
A practical daily amount would be below the dose that caused symptoms. Some people begin with approximately 50% to 75% of the tolerated amount, divided into smaller doses.
Using the example above, that might mean taking 750 to 1,000 milligrams daily, divided between morning and afternoon.
Your tolerance is not a permanent prescription. Diet, stress, illness, digestion and other factors may change how you respond.
Who should avoid this DIY experiment?
Speak with your healthcare practitioner before experimenting with higher-dose vitamin C if you have:
- Kidney disease or reduced kidney function
- A history of calcium-oxalate kidney stones
- Hemochromatosis or another iron-overload disorder
- G6PD deficiency
- An inflammatory bowel condition or chronic diarrhea
- An upcoming medical procedure
- Pregnancy or breastfeeding
- Active cancer treatment
- Prescription medications that may interact with supplements
High supplemental doses may increase kidney-stone risk in susceptible individuals. Vitamin C also increases nonheme iron absorption, which can be a concern for people with iron-overload conditions. High doses can be particularly dangerous for someone with G6PD deficiency.
Stop immediately if you experience persistent diarrhea, severe abdominal pain, vomiting, weakness, dizziness, flank pain, reduced urination or blood in the urine.
When do I recommend higher doses of vitamin C?
Persistent fatigue is the main reason that I recommend a bowel tolerance experiment and daily doses of vitamin C. Fatigue is often a mysterious symptom that can be related to so many conditions and have so many causes. Vitamin C doesn’t solve or cure any specific problem; rather, it strengthens your immune cells and lowers your oxidative stress. This is a systemic solution at a cellular level.
One main reason for fatigue is adrenal stress, burnout or fatigue. Your adrenal glands make cortisol, which is known as your stress hormone. Most people, including me, live a very stressful modern life that literally burns up the cortisol your body naturally makes, and demands that your adrenal glands make more. Your adrenal glands use vitamin C and other nutrients to keep up with the demands of making cortisol. So the formula for supporting your adrenal glands is rather simple: extra vitamin C and reducing stress in your life. It sounds easy and I know it can be complicated.
If you're interested in learning more about Vitamin C supplements or gaining a healthier lifestyle, or if you just can't find the information you are looking for, set up an appointment with me and I'll help you find the answers you are looking for!
