High-Dose Vitamin C: Benefits and Risks

High-Dose Vitamin C: Benefits and Risks

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin that’s naturally present in some foods, can be added to others, and is also available as a dietary supplement. Historically, vitamin C has been used to prevent scurvy and other illnesses associated with its deficiency. Today, ascorbic acid is broadly touted as a natural defense against common colds with immune-boosting capabilities.

Humans, unlike most animals, cannot synthesize vitamin C, which makes it a vital dietary nutrient. It is required for the biosynthesis of collagen, L-carnitine, and a variety of neurotransmitters. Vitamin C is also essential in the healing of wounds, as well as repair of teeth, bones, and cartilage. As an antioxidant, this vitamin can also neutralize free radicals that are responsible for cellular damage.

Vitamin C has also been shown to regenerate other antioxidants in the body, including alpha-tocopherol (Vitamin E). Ongoing streams of studies are examining whether Vitamin C can limit the development of certain cancers, cardiovascular diseases, and other illnesses in which oxidative stress plays a fundamental role. Natural sources of vitamin C include Brussels sprout, broccoli, strawberries, citrus fruits, kiwi, papaya, watermelon, mango, cantaloupe, spinach, pineapple, and red/green peppers, among others.


Benefits of High-Dose Vitamin C

The number of people intrigued by the benefits of high dose vitamin C therapy in San Diego has increased dramatically over the last few years. This is probably due to the buzz created regarding adjunctive treatment of cancer with vitamin C at high-doses. So, is it possible to take too much vitamin C? Are there proven benefits? The answer to both of these questions is, Yes! Since vitamin C, as are B vitamins, is water-soluble, excess amounts can be consumed and excreted, and do not accumulate in the body. Higher doses of vitamin C can add antioxidant benefit up to 25g intravenously. At doses higher than 25g, Vitamin C can provide a pro-oxidant effect and actually cause destruction to cells.

  • Beneficial for Cancer Treatment 

Since the 1970s, some researchers have suggested that high doses of intravenous vitamin C, along with cancer drugs, could improve the treatment of cancer. IV vitamin C is shown to produce very high levels of the vitamin in the body, which can help in fighting cancer cells while providing minimal damage to the body’s cells. Some experimental results have also shown that high doses of vit C can reduce the side effects of cancer drugs.

For example, the National Cancer Institute reports that two studies have found that patients who received IV vitamin C have a better quality of life and fewer side effects than those who didn’t. In the same report, a study of healthy volunteers and cancer patients revealed that vitamin C doses of up to 1.5g/kg could be safe in patients who don’t have kidneys diseases or G6PD deficiency.

Surveys of healthcare practitioners at the United States CAM conferences have indicated that high-dose IV vitamin C is often given to patients as a treatment for a variety of infections, fatigue, as well as cancers, including breast cancer. However, the potential benefits of both oral and intravenous ascorbate vitamin C in cancer treatment remains massively controversial. For example, a recent study published in NCBI found unsatisfactory evidence to determine if IV vitamin C was beneficial for cancer treatment.

  • Weight Loss 

High vitamin C dosage, whether intravenous or oral, is sometimes used for weight loss. A 2005 study found evidence that people who vitamin C deficient aren’t able to burn fat well, which in turn can cause weight gain. This suggested that adequate intake of vitamin C can help in weight loss or at least prevent weight gain. However, there are no recent supplementary studies that show that high-dose intake of vitamin C can cause weight loss.

  • Immune Function 

Some people take high doses of vitamin C for general health and to boost immune function. This is common for people who don’t take the vitamin often and may do so for convenience. As noted previously in this post, vitamin C is essential for general health, and some studies have reported high intakes can lead to improved immunity.

Risks and Side-Effects of High-Dose Vitamin C 

Clinical trials have shown that there are few vitamin C side effects when taken both orally or intravenously. However, some trials have reported a number of risk factors that make high-dose vitamin C harmful and potentially dangerous.

  • Since vitamin C increases the absorption and use of iron in the body, high doses of the vitamin are not recommended for patients with hemochromatosis—a condition where the body takes up and stores more iron than it needs. Excess iron can poison organs, leading to conditions such as cancer, cirrhosis of the liver, and irregular heartbeat.
  • Studies have also shown that patients with an inherited condition known as G6PD should not be given high doses of vitamin C since this can increase the chances of hemolysis, a condition where red blood cells are destroyed.
  • Case reports have also evidenced that high ascorbic treatment can also increase risks of kidney failure in patients with high tendencies of developing kidney stones. Excess vitamin C is excreted from the body as a waste product in the oxalate formOxalate normally exits from the body via urine, but under some circumstances, this compound may bind to minerals and form crystals that can lead to the formation of kidney stones.  As such, patients with a history of kidney stones or disease should proceed with caution and discuss high-dose vitamin C treatment with his or her doctor.
  • Mega-doses of vitamin C supplements might also cause a variety of side effects, including diarrhea, nausea, heartburn, vomiting, insomnia, headache, abdominal cramps, and bloating, among others.

Treatment Therapy 

For treating patients with vitamin C deficiency, the typical dose of the vitamin C is 200 mg once every day for up to one week. For off-label purposes, however, a wide variety of vitamin C doses have been used to treat different ailments. Such doses usually range anywhere between 10 to 100 grams intravenously and much lower doses orally. Consult your doctor on what doses and scheduling are appropriate for your individualized vitamin C therapy.