CategoriesVitamin C

Unveiling the Myth: Is Excessive Vitamin C Harmful

Welcome to a journey of discovery and discernment with ‘Unveiling the Myth: Is Excessive Vitamin C Harmful?’ In this enlightening exploration, we’ll dive deep into the vibrant world of Vitamin C, a nutrient celebrated for its myriad health benefits. From warding off colds to promoting radiant skin, Vitamin C has long been hailed as a wonder vitamin. But amidst this chorus of praise, a critical question lingers – can one have too much of this good thing?

Join us as we unravel the science behind Vitamin C, examining its role in our bodies, the truth about its recommended dosages, and the potential risks of overconsumption. Prepare to be informed, surprised, and empowered with knowledge, as we uncover the fine line between beneficial and excessive, and reshape your understanding of this beloved vitamin.

A serene landscape at sunset with a vibrant orange sun reflecting over a calm lake, a wooden table foreground with citrus fruits, and a laboratory flask with orange liquid.
Exploring the Balance: Nature’s Bounty and Scientific Inquiry into Vitamin C

First, what is Vitamin C?

  • Water-soluble vitamin; essential for all humans. One of vitamin C’s most known functions is the support of immune health. Vitamin C supports various cellular functions of both the adapt and innate immune system [8]. Now more than ever, we need our immune systems to be functioning optimally! 
  • Its biological function is based on its ability to provide reducing reactions, which eliminate reactive oxygen species (ROS).
  • Reactive species cause oxidative stress and DNA damage. DNA damage leads to more serious disease such as: [1]
  • Cancer
    • Cardiovascular disease
    • Cataracts
    • Age-Related Macular Degeneration
    • Central Neurodegenerative Disease
    • Diabetes Mellitus
    • Premature Aging
  • Vitamin C’s ability to reduce oxygen species makes it a powerful ANTIOXIDANT!!!

Antioxidant is a huge part of anti-aging”     

How much vitamin C is too much?

In a study done by Reilly et al., 2.0 g of vitamin C was supplemented to smokers, for 5 days. After the 5 days there was a significant reduction of urinary isoprostanes (an indicator of oxidative stress). Alluding to the powerful antioxidative properties of vitamin C!

  • How much is 2.0 g of Vitamin C? 1000 milligrams (mg) = 1 gram
  • The serving size of OPTIMUNITY® is two capsules at 1500 mg of vitamin C – TOTALLY DOABLE!
  • You should be able to get all the vitamin C you need in your diet
  • Vitamin C cannot be stored in the body, you need it in your diet every day

How much vitamin C should you take?

“If you’re not a smoker, do you take 2.0 g of vitamin C a day?”

  • Always talk to your doctor before taking any supplements! You don’t want vitamins interfering with any prescribed medication you’re already taking.
  • I was a vegan for a long time, and it resulted in severe anemia. Anemia that was completely undetected until I was in a car accident (YIKES!) I take 2 OPTIMUNITY®, currently, because vitamin C helps you absorb iron. My doctor suggested this for me, I did not start this on my own!!!
  • I will say- I had to take vitamin-C and eat steak every night before my surgery to counteract my severe anemia and my iron went up, up, up, in just a couple of days!


What happens if you take too much vitamin C?

Taking too much vitamin C could cause gastrointestinal problems, but for the most part the toxicity levels of vitamin C is low. Unless taken with certain medications, too much vitamin C would only cause temporary disturbances.

Large amounts of vitamin C are administered at the hospital for major trauma patients. Plasma concentrations of Vitamin C are depleted during the following traumas: [2]

  • Severe critical illness
  • Major trauma
  • Burns
  • Intravenous vitamin C is given to trauma patients in order to combat oxidative stress and promote wound healing.

“If you aren’t suffering from a trauma should you be taking large amounts of vitamin C?”

The answer is…. NO.

 High levels of Vitamin C (way more than 2.0 grams a day) show cytotoxicity in cancerous and non-cancerous cells. Clearly- there is too much of a good thing noting the two-face characteristic of vitamin C [3].

  • Killing cancer cells -YAY!
  • Killing healthy cells – NAY!

High levels of vitamin C showed toxic effects on proliferating stem cells. But not differentiated cells this is due to higher expression of Glut genes [3] This was also the case when vitamin C was exposed to cancer cells, DNA damage was induced in the cancer stem cells but the differentiated cancer cells were not as susceptible.

“It is suggestive that IVC has important antitumor activity. IVC may improve the quality of life and symptoms of patients with cancer. These finding are not conclusive but suggestive; controlled studies of IVC therapy are needed.” [5]

How much Vitamin C can you take a day?

Vitamin C is considered a dietary supplement. YES, you can take it if you’re not on a diet. The guidelines for dietary supplements are [4].

  • If the product includes one or more dietary ingredients including:
    • Vitamins
    • Minerals
    • Herbs
    • Other botanicals
    • Amino Acids
    • Enzymes
    • Tissues from organs or glands
    • Extracts of the previous listed
  • AGAIN, Talk to your doctor!
  • A good place to start is following the directions labeled on any supplement bottle. Federal regulations state that dietary supplement companies are responsible for having evidence that their products are safe. According to the NIH the following are regulation guidelines:
  • Supplements need to be produced in a quality manner
    • Ensure the supplements don’t contain contaminants or impurities
    • Accurate labeling
  • Be careful taking any dietary supplement if you are nursing, pregnant, or giving it to a child. According to the NIH most supplements are not tested on these individuals and we don’t know their safety level.

Vitamin C for Dermatological use

Normal Skin contains high concentrations of vitamin C, which stimulates collagen synthesis and assists in antioxidant protection against UV photodamage. [6]

Due to the high concentrations of vitamin C naturally found in our skin, the beauty industry uses this rationale to promote topical vitamin C for the skin. But are vitamin C topicals efficient at turning back the clock?

Topical Vitamin C vs. Dietary Vitamin C6

  • What is the function of the skin?
    • It is our first line of defense from weather, chemicals, pollutions, and bacterial insults.
  • The constant contact with the environment leads to the most visible signs of aging than any other organ
  • Nutritional efficacy is so important for maintaining normal skin function, collagen synthesis and keratinocyte differentiation are two main skin processes that maintain the integrity of the skin.
  • Due to the constant environmental defense of skin, it NEEDS antioxidants to beat free radial stress.
    • Vitamin C, Vitamin E, and selenium and imperative for antioxidant defense and protection against UV damage.

Topical application of Vitamin C would need to penetrate the top, thick layer of the dermis in order to reach the cells that are not targeted by the underlying blood vessels, the nutritional blood flow under the skin flow in the direction of the arrows. 

The top layer of skin acts as aqueous barrier and prevents passage of many substances6. Some particles can penetrate the upper layer of the skin, but it is very unlikely for the topical supplements to penetrate into the deep layers of the dermis, nutrient delivery is best when delivered through the bloodstream via dietary intake. 

Vitamin C deficiency in the skin [6]

  • Poor wound healing due to lack of collagen formation
  • Thickening of the outer dermal layer
  • Subcutaneous bleeding due to fragility and loss of connective tissue integrity

Importance of Vitamin C in the skin

  • Promotion of Collagen formation
  • Ability to scavenge free radicals and dispose of toxic oxidants
  • Inhibition of Melanogenesis
  • Interaction with cell signaling pathways (differentiation of keratinocytes)

What is liposomal Vitamin C?

The body cannot properly store vitamin C. Delivery and utilization of vitamin C in the body needs to be specialized in order to optimize biological use of vitamin C.

Liposomal delivery seems to be most efficient. Liposomal delivery refers to the delivery of supplements via a lipid vesicle7. Liposomes are used to encapsulate and transport ingredients in drugs and supplements to parts of the body where they are most efficiently absorbed.

OPTIMUNITY® gives you optimal immunity based on its liposomal delivery. Liposomal delivery is BEST for biological absorption. We need vitamin C in our diets every day! Fruits and vegetables are clearly important for many different reasons, but as we can see from the list below even at 95 mg per serving, we are only getting 3% of the vitamin C content of OPTIMUNITY®.

Content of Vitamin C in fruits and vegetables

Foodmg per Serving
Red Pepper 1/2 Cup95
1 Orange93
Grapefruit Juice 3/470
1 med. Kiwifruit64
Green Pepper 1/2 cup60
Broccoli 1/2 cup51
Strawberries 1/2 cup49
Brussels Sprouts 1/2 cup48
Graprefruit 1/2 medium3.9
Tomato Juice 3/4 cup33
Cantaloupe 1/2 cup29
Cabbage 1/2 cup28

Frequently Asked Questions Excessive Vitamin C

I have acne, since Vitamin C is good for your skin, would it help clear up my breakouts?

Possibly, but there are so many reasons for acne. It could be caused by hormonal reasons, bacterial reasons, abundance of oil production, or systemic inflammatory reasons. Speak with a dermatologist to determine the route cause. Also, you can use topical vitamin C, and increase your dietary intake of Vitamin C and see if it helps or hinders.

I have irritable bowel syndrome (IBS) could an increase in Vitamin C cause my IBS to be worse?

It’s very possible that any dietary changes could make your IBS worse. Too much vitamin C has been known to cause stomach pain, diarrhea, and flatulence. I have suffered with IBS and the best thing to do is keep a food journal, write down how certain foods make you feel. If you have an adverse reaction, cut it out!!!

Should men and woman take different amounts of vitamin C?

Yes, dietary intake is different for sexes and for age brackets. According to the National Health and Nutrition Examination Survey (NHANES) mean intake of vitamin C for adult men is 105.2 mg/day. Mean intake for adult females is 83.6 mg/day. For children aged 1-18 years old, the mean intake of vitamin C ranges from75.6 -100 mg/day. These numbers should be higher for smokers.

Will I become symptomatic if I do not get enough vitamin C?

Yes, but typically, your low levels of vitamin C would have to be chronic. Meaning, a month or longer with vitamin C levels below 10mg/day. Your initial symptoms may include fatigue, malaise, and inflammation of the gums [7]. After a very long time of low levels of vitamin C you would experience petechia, ecchymoses, purpura, joint pain, poor wound healing, hyperkeratosis, and corkscrew hairs7. Iron deficiency anemia can also be caused by a decrease of vitamin C intake.

Are there groups of people more at risk for vitamin C deficiency?

Yes, smokers, infants that are fed evaporated or boiled milk, individuals with poor diets and lack of food variety, and people with chronic diseases that have trouble absorbing nutrients

Can vitamin C interact with my prescriptions?

Vitamin C has a low toxicity, but it is a supplement that could potentially interact with different medications. People on chemotherapy, radiation, and statins should be careful of their vitamin C intake.

Can you take too much vitamin C?

Yes, as we previously stated, vitamin C has a low toxicity rate. You would have to take a lot in order to make you sick, but it also has a threshold of absorption. Once you take more than 1 gram a day the absorption falls to 50% and the rest is excreted in the urine.