The Chemistry Of L-Ascorbic Acid Or Vitamin C?
- Nov 8, 2024
- 8 min read
Updated: Aug 2
Ida is a certified aesthetician (graduate of Marvel School of Beauty), offering home-based services since 1994. Ida provides various holistic services. She graduated from Zanqara’s Skin Care’s Dermatician course in 1994, which required her to understand homeopathic remedies.

Vitamin C is known for helping skin health and overall wellness. L-ascorbic acid, the active form of Vitamin C, is common in supplements and skincare. On the skin, it gently exfoliates and brightens. In this article, we’ll compare isolated L-ascorbic acid with Vitamin C from whole foods, explain how it’s made, and discuss how the body and skin absorb these forms. We’ll also talk about Vitamin C’s stability in skincare and the challenges brands face when using this antioxidant.

Natural vitamin C components
Vitamin C is water-soluble and acts as a strong antioxidant. When you get it from whole foods, it comes with other helpful nutrients like flavonoids and rutin. These nutrients work together to support your body and increase antioxidant benefits.
L-ascorbic acid: A simplified vitamin C component
L-ascorbic acid is the main component of Vitamin C responsible for its health benefits. It is often used in supplements and skincare. While isolated L-ascorbic acid provides targeted antioxidant support, whole foods deliver it along with other nutrients. For this reason, some people prefer to get Vitamin C from whole foods to benefit from all the nutrients working together.
The role of complete vitamin C in the body
Vitamin C helps your body make collagen, which keeps your skin, tendons, ligaments, joints, and bones strong. It also helps wounds heal, keeps blood vessels healthy, and supports your adrenal glands. As an antioxidant, Vitamin C protects your cells from damage and helps restore Vitamin E. Because our bodies can’t make or store Vitamin C, it’s important to eat foods rich in it.
Skin benefits of vitamin C
Reduces the appearance of fine lines and wrinkles
Visibly improves skin texture and colour.
Protects the skin against ambient moisture loss and oxidative stressors
Supports healthy collagen production to maintain a youthful appearance
Factors that reduce vitamin C in the skin
Natural chronological aging
Environmental stressors like excessive UV exposure or pollution
Lifestyle elements such as chronic stress, smoking, or heavy alcohol consumption
Periods of high physiological stress or illness
How does the body use vitamin C and L-ascorbic acid?
Vitamin C and L-ascorbic acid are important antioxidants that support key processes in your cells. In the body, Vitamin C is recycled through the Redox Cycle. During this process, oxidized Vitamin C (called dehydroascorbic acid, or DHA) is converted back to its active form. DHA enters cells easily and is changed back into ascorbic acid with help from glutathione and NADPH.
The body uses both natural and synthetic L-ascorbic acid in the same way. However, taking high doses of isolated Vitamin C can affect some body processes differently. In some cases, when there is free iron present, ascorbic acid can act as a pro-oxidant through what is called the Fenton reaction.
The Fenton Reaction occurs when free iron (Fe2+) reacts with hydrogen peroxide (H2O2) to create hydroxyl radicals. Ceruloplasmin, an enzyme produced by the liver, helps convert Fe2+ to Fe3+, which helps the body manage iron. How our cells control iron and handle oxidation is complex. Keeping your metabolism healthy and getting enough essential nutrients help your body manage iron and reduce oxidative stress.
"Please note that different oxidative stress mechanisms occur in Redox Cycling and the Fenton Reaction."
If the body doesn’t regulate iron properly, more free Fe²⁺ can build up. This can trigger the "Fenton Reaction and cause oxidative" stress, which may also harm ceruloplasmin or other mechanisms the body uses to control iron. Iron metabolism and oxidative stress can affect each other.
L-ascorbic acid production
Most of the world’s L-ascorbic acid is made in several steps. First, glucose from stable sources, such as corn syrup, is converted to sorbitol; special bacteria change sorbitol into sorbose. After more chemical and purification steps, this process produces pure L-ascorbic acid.
Possible causes of oxidative stress
If the body can’t recycle ascorbic acid quickly enough, dehydroascorbic acid builds up and breaks down into other compounds like 2-3 diketogulonic acid and oxalic acid. This can cause more oxidative stress if ascorbic acid isn’t restored efficiently.
If the body runs low on glutathione and NADPH, it can’t regenerate ascorbic acid as well, which lowers its overall antioxidant power.
Some nutrition experts recommend balancing high doses of single nutrients with your overall mineral intake to keep your body in balance.
Excess synthetic L-ascorbic acid supplementation contraindications
Considerations with iron absorption
Be cautious: Vitamin C helps your body absorb more non-heme iron. If you have an iron overload condition like hemochromatosis, talk to your doctor before taking high-dose Vitamin C supplements.
If you are prone to calcium oxalate kidney stones, watch your Vitamin C intake, as too much can raise oxalate levels in your urine. Pregnant people or anyone with health conditions should check with a health professional to find the right dose.
Pro-oxidant effects of topical L-ascorbic acid
Very acidic L-ascorbic acid products can sometimes cause mild irritation or redness, especially for sensitive or acne-prone skin. If the product gets too oxidized, it loses its antioxidant power and won’t help your skin as much.
Interactions with copper peptides
Copper peptides are highly reactive. Some skin care regimens suggest waiting at least 15 minutes between using L-ascorbic acid and copper peptides to keep the ingredients effective. Others recommend using them at different times of day for the best results.
Metal ingredients and products causing the Fenton Reaction
Small amounts of minerals like copper and iron can react with active ingredients in skincare and cosmetics. Understanding these interactions helps product makers keep formulas stable and last longer.
Formulating and choosing L-ascorbic acid products in skincare
L-ascorbic acid is effective for brightening skin and reducing signs of aging, but it isn’t very stable. Its strength drops when exposed to air, heat, or light. Most products use up to 20% L-ascorbic acid at a pH of 2 to 3.5 for best results. If you have sensitive skin, it’s best to start with a lower concentration to avoid irritation.
Essential skincare tips for L-ascorbic acid use
Ingredients to avoid
Don’t use Retinol and active Vitamin C in the same layer, as this can make your skin more prone to irritation. Also, avoid using Vitamin C right after AHAs (Alpha-Hydroxy Acids), as this can alter the pH and increase sensitivity.
It’s best to use L-ascorbic acid at night to protect it from light. If you use it during the day, consistently apply a broad-spectrum sunscreen afterward to protect your skin.
L-ascorbic acid stays stable longer when it’s combined with other antioxidants like Vitamin E and ferulic acid.
Store your products in a cool, dark place or in the fridge to help them stay fresh and last longer.
Oxidized synthetic L-ascorbic acid
If your product turns orange or dark brown, it means the active ingredient has oxidized too much. When this happens, it won’t work as well and should be replaced. replaced.
Common foods high in vitamin C
Eating a variety of fresh whole foods, such as bell peppers, strawberries, blackcurrants, broccoli, Brussels sprouts, potatoes, cantaloupe, persimmons, and citrus fruits, is a great way to maintain healthy vitamin C levels.
Heat can reduce the amount of vitamin C in food, so cooking lightly helps keep more of it. Foods especially high in vitamin C include acerola cherries, some rose hips, and greens like amaranth, pokeweed, wild leek, and watercress. Wild berries such as currants, elderberries, gooseberries, and cloudberries are also great sources. Research shows that crops grown in direct sunlight have more vitamin C than those grown in greenhouses.
Recommended vitamin C intake
Health Canada recommends 90 mg of Vitamin C per day for adult men and 75 mg for adult women. Most people who eat enough fruits and vegetables get enough. Since the body removes excess water-soluble vitamins, taking very high doses isn’t usually needed.
Conclusion
Vitamin C is important for many body functions, such as protecting cells and helping make collagen. You can get it from whole foods or as isolated L-ascorbic acid. Isolated forms are strong and common in supplements and skincare, but whole foods provide extra nutrients that work together. If you take high doses of isolated supplements, make sure to keep your nutrient balance to avoid extra oxidative stress.
Groups like the Environmental Working Group (EWG) rate skincare products based on their quality and formulation. Making a good topical Vitamin C product is challenging because it can break down easily when exposed to light, heat, or air. For best results, eat a diet rich in whole-food Vitamin C and use stable, well-made topical products. Also, since most isolated L-ascorbic acid comes from corn, people with corn allergies may want to choose whole-food Vitamin C instead.
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Ida Fanelli, Aesthetician, Reflexologist & IPL & Dolphin MPS Technician
Ida is a dedicated wellness professional and certified aesthetician (Marvel School of Beauty), providing personalized, home-based services since 1994. A certified reflexologist since 1993 (D'Arcy Lane Institute), she has integrated energy therapies and Ion Cleanse foot wellness sessions since 1998. In 2012, she became a certified Sharplight IPL Technician for skin rejuvenation and pigmentation correction, and in 2019 earned a specialized certification from the Center for Pain and Stress Research, using the Dolphin Neurostim system for Microcurrent Point Stimulation to support scar tissue release, skin rejuvenation, and pigmentation lightening. Ida is deeply committed to continuing education in complementary health to provide accessible, high-quality care. She also brings 12 years of experience as a hospital laboratory technologist in Microbiology and Biochemistry to her meticulous practice.
Disclaimer:
Educational and Informational Purposes Only: The information provided in this article is meant exclusively for educational, informational, and general wellness purposes. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
Not Medical Advice: Always seek the advice of a qualified healthcare practitioner or medical professional with any questions you may have regarding a medical condition, dietary supplements, or specific nutritional needs. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.
Regulatory Note: The dietary recommendations discussed herein reflect the standard baseline metrics established by Health Canada. However, individual nutritional requirements vary based on personal health status, lifestyle, and medical history.
Cosmetic and Formulation Content: The skincare and cosmetic formulation details mentioned are for educational purposes regarding product stability and ingredient characteristics. Topical applications may cause individual sensitivities. If skin irritation or a reaction occurs, discontinue use immediately and consult a dermatologist or healthcare professional.
The inclusion of external references, theories, or third-party frameworks does not imply endorsement of unapproved therapeutic procedures.
To learn more, here is some related information: Cure Your Fatigue: Morley Robbins
References:
Thyroid Nation: Balance Copper with Ceruloplasmin for Thyroid Health
Industrial production of L-ascorbic Acid (vitamin C) Wikipedia
Low Energy? Feel Like Sh**? Consider Getting to the “Root Cause” with Morley Robbins
The Root Cause of Fatigue with Morley Robbins: Episode 2 The Myths Around Vitamins C and A
George Brewer Risk of Copper and Iron Toxicity during Aging in Humans PMID 19968254
Is L-Ascorbic Acid Better Than Synthetic Vitamin C for Skin Health?
Topical Vitamin C and the Skin: Mechanisms of Action and Clinical Applications
Two Faces of Vitamin C—Antioxidative and Pro-Oxidative Agent
Two Faces of Vitamin C—Antioxidative and Pro-Oxidative Agent
For the best skin, I don’t take vitamin supplements except for one.
The Scientific Papers Supporting Vitamin C Serum’s Skin Benefits are Flawed
https://www.sciencedirect.com/science/article/abs/pii/S030442382030501X









