The Truth About Vitamin C Therapy and Cancer Cells

Most people think of vitamin C as something you take when you feel a cold coming on. It is often marketed as an immune booster or a simple vitamin that helps you get through the flu season. But biologically, vitamin C is far more important than that. It plays a foundational role in human physiology and supports processes that are essential for life itself.

One of the most revealing facts about vitamin C is that almost every animal on Earth produces it inside their own body. Dogs make vitamin C. Cats make it. Sharks, bears, amphibians, and fish all manufacture it internally as part of their normal biology. Their bodies continuously produce vitamin C because it is necessary for survival.

Humans are different.

Only five species on Earth lack the ability to make their own vitamin C: humans, monkeys, apes, guinea pigs, and fruit bats. Every other creature produces it naturally. This fact alone tells us something important about the molecule. When nearly every species depends on a nutrient enough to produce it themselves, it is clearly fundamental to life.

Somewhere along the evolutionary path, humans lost the gene responsible for producing vitamin C. As a result, we must obtain it through food or supplementation every single day. If we do not get enough, critical systems throughout the body begin to suffer.

Why is Vitamin C Essential to Human Physiology?

Vitamin C, also known as ascorbate, is central to countless biochemical reactions that keep cells alive and functioning. At the most fundamental level, life depends on the transfer of electrons from one molecule to another. These reactions power metabolism, cellular repair, and the processes that maintain homeostasis.

Vitamin C donates electrons in a precise, controlled way that helps maintain cellular balance. Scientists describe this as part of the body's redox system, which allows cells to generate energy efficiently while protecting them from oxidative damage.

Beyond electron transfer, vitamin C is required for the production of several critical neurotransmitters, including dopamine, serotonin, and epinephrine, which influence mood, focus, and the stress response. Without adequate vitamin C, neurotransmitter synthesis can be impaired, affecting both brain function and overall physiological balance.

Vitamin C also supports connective tissue, blood vessels, collagen formation, immune function, and wound healing. Its role touches almost every major system in the body, making it far more than a simple dietary supplement. It is a molecule fundamental to life itself.

Vitamin C and Epigenetic Regulation

Another key role of vitamin C is in epigenetic regulation, the system by which cells control which genes are active or silenced. While every cell contains the same DNA, cells behave differently depending on which genes are expressed. This allows the body to adapt to environmental changes and maintain proper function.

Sometimes, epigenetic patterns can become disrupted due to stress, inflammation, or metabolic changes. Vitamin C supports the function of enzymes that help correct these epigenetic alterations, restoring healthy gene expression and preventing cells from behaving abnormally.

By supporting epigenetic health, vitamin C helps maintain proper cell identity and function, reducing the likelihood that cells will take on dangerous behaviors, such as uncontrolled growth or metabolic dysfunction.

Vitamin C and Cancer (CFCs)

Dr. Thomas Lodi often refers to cancer cells as CFCs, or chronically fermenting cells, to emphasize a core biological feature: these cells rely heavily on fermentation for energy rather than oxygen-based metabolism, unlike healthy cells. This metabolic shift allows cancer cells to survive and grow even in challenging conditions.

Understanding cancer as CFCs (chronically fermenting cells) helps explain why certain therapies, like high-dose vitamin C, can selectively target these abnormal cells. While healthy cells are protected by enzymes that neutralize oxidative stress, CFCs are often more vulnerable.

Vitamin C supports enzymes that regulate HIF-1α (hypoxia-inducible factor 1 alpha), a pathway CFCs use to survive in low-oxygen conditions. By influencing this pathway, vitamin C makes it harder for cancer cells to thrive under stress.

It also weakens the protective systems that cancer cells use to survive oxidative stress, making them more vulnerable to targeted therapies.

Oral Vitamin C: Supporting Daily Physiology

Oral vitamin C, typically in the form of ascorbic acid or sodium ascorbate, plays a key role in maintaining basic physiological functions, including immune support, neurotransmitter production, and tissue repair. However, the digestive system limits absorption to roughly 300–400 milligrams per dose, and excess amounts are either excreted or can cause gastrointestinal discomfort. Because of this absorption ceiling, even large oral doses result in only modest increases in plasma concentration, which are sufficient for general health but do not reach the levels required to directly affect CFCs, or chronically fermenting cells (cancer cells).

Liposomal Vitamin C: A More Efficient Oral Option

Liposomal vitamin C is a more advanced oral delivery method in which the vitamin is encased in a phospholipid layer. This allows higher amounts to enter the bloodstream efficiently, bypassing some of the absorption limits of standard oral forms. Liposomal vitamin C still supports all the fundamental physiological functions of vitamin C—including immune health, neurotransmitter synthesis, and tissue repair—but achieves higher circulating levels than conventional oral supplements, making it a more effective option for maintaining overall cellular health.

IV Vitamin C: Achieving Therapeutic Plasma Levels

While oral and liposomal vitamin C maintain daily physiological functions, intravenous (IV) vitamin C is unique in its ability to reach pharmacological plasma concentrations that can directly target cancer cells. At these high levels, vitamin C generates hydrogen peroxide in the fluid surrounding cells. Healthy cells have protective enzymes to neutralize it, but many CFCs lack this defense, making them selectively vulnerable to oxidative stress. Research and clinical protocols suggest plasma concentrations of roughly 350 milligrams per deciliter are required to achieve these effects. Below this threshold, vitamin C primarily supports normal physiology rather than exerting a direct anti-cancer effect.

The Importance of Monitoring Plasma Levels

A crucial, often overlooked step in IV vitamin C therapy is measuring plasma levels. After an infusion, blood tests confirm whether the therapeutic concentration was reached. Many clinics do not routinely perform this monitoring, so patients may receive IV vitamin C without knowing if the dose was effective. Individual differences, such as metabolism, body composition, and baseline vitamin C levels, can affect how plasma concentrations respond. At An Oasis of Healing, we carefully measure plasma levels and track all treatments to ensure each infusion achieves its intended therapeutic target. This precise monitoring maximizes effectiveness, maintains patient safety, and ensures that IV vitamin C delivers its full potential in supporting cellular health and complementing integrative cancer care.

Understanding Vitamin C as More Than a Vitamin

Vitamin C is far more than a simple supplement or immune booster. It regulates gene expression, supports neurotransmitter synthesis, maintains connective tissue, strengthens immune defenses, and influences the metabolic environment in which cancer cells grow.

High-dose IV vitamin C can selectively target cancer cells (CFCs), while liposomal oral supplementation ensures daily physiological needs are met. By understanding how vitamin C works, patients and practitioners can use it strategically, rather than just taking it casually.

At An Oasis of Healing, vitamin C is part of a comprehensive integrative approach that supports cellular health, gene regulation, immune function, and targeted therapy for cancer. To learn more about treatment options, visit our Become a Patient page.