Vitamin C Health Benefits and Daily Intake

Fruits and Vegetables
Fruits and Vegetables

A character in Margaret Atwood’s novel The Robber Bride cleverly used vitamin C deficiency as a manipulation tactic. She wanted others to think that she had cancer. The idea of intentionally becoming nutritionally deficient to manipulate others was horrifyingly fascinating. But manipulation tactics aside, is it possible to have a vitamin C deficiency today? What role does vitamin C play in the body? What are its health benefits? What are the best sources and how much should we consume?

Vitamin C Deficiency

It is possible to have a vitamin C deficiency if you do not get enough fresh fruits or vegetables in your diet and don’t take supplements; if you have a lifestyle that contributes to vitamin C insufficiency in the diet by overcooking foods or eating mostly processed foods; or by engaging in activities such as smoking, which depletes the body of vitamin C.

Signs of a deficiency include bleeding gums, fatigue, more frequent colds or infections, bruising, joint pain, wounds that heal slowly and digestive problems. Scurvy is not so common these days, but the symptoms of it are wounds that don’t heal or take very long to heal, soft gums that bleed easily, lethargy, water retention and bleeding under the skin.

Health Benefits of Vitamin C

Vitamin C (ascorbic acid) helps the body in many ways. It helps the body to absorb iron, it works with vitamin E and beta-carotene in the body as an antioxidant, it contributes to collagen formation, adrenal function, and promotes healthy gums.However, you should be careful with chewable forms of vitamin C as they can damage tooth enamel. Vitamin C also helps to strengthen the immune system and assists the body in metabolizing folic acid, tyrosine, and phenylalanine.

Vitamin C is credited with helping to prevent or shorten the duration of the common cold. It is also said to improve asthma symptoms, counter the toxic effects of pollution, and help the body rid itself of heavy metal toxins by rendering them ineffectual so they can be flushed out. It can alleviate joint pain, increase energy, and aid digestion. It is also easy to obtain from food.

Sources of Vitamin C

Unlike vitamin D, which we can get free from the sun, we need to receive our daily allowance of vitamin C from the food that we eat or from supplements. Vitamin C is heat sensitive, which means that cooking food that contains vitamin C will destroy most of the vitamin C content in the food. In their book The Art of Raw Living Food (Hay House, 2009), Doreen Virtue and Jenny Ross state that cooking can destroy up to 80% of the vitamin C in a food.

Good sources of vitamin C are citrus fruits, Brussels sprouts, berries, sweet peppers, various greens, asparagus, rosehips, and many other fruits and vegetables. Herbs such as alfalfa, cayenne, peppermint, nettle and parsley also contain vitamin C. Dr. Tony O’Donnell, in his book Miracle Super Foods that Heal (O’Donnell, 2001), lists acerola berry juice powder as “one of the most potent natural sources of vitamin C anywhere.”

Recommended Daily Allowance of Vitamin C

The amount of vitamin C you may require varies depending on your health and some lifestyle variables. The Recommended Daily Allowance (RDA) of vitamin C for adults based on a chart from Health Canada is 75 to 90 mg/day, with more recommended for women who are breastfeeding and less for women who are pregnant.

Natural food enthusiasts tend to take more than the RDA. In the book Eating in the Light, Doreen Virtue and Becky Prelitz recommend 100 to 1,000 mg of ascorbic acid. Since some of these recommendations are quite high, it’s natural to wonder if there is any potential for toxicity.

Maximum Doses of Vitamin C

Since vitamin C is water soluble, it is possible to take fairly large amounts of it, but you should still exercise caution. Taking too much vitamin C could cause diarrhea at the very least, and daily doses greater than three grams may be related to the formation of kidney stones, according to Martha Davis, Ph.D., Elizabeth Robbins Eschelman, MSW, and Matthew McKay, Ph.D. in their book The Relaxation & Stress Reduction Workbook, Fifth edition (New Harbinger Publications, 2000). Health Canada’s chart lists the upper limit for the RDA for adults as 2,000 mg/day.

However, O’Donnell says in Miracle Super Foods that Heal that he personally takes 4,000 to 8,000 mg/day of vitamin C and that his mentor, Jay Patrick, takes 20 grams per day. The scientist Dr. Linus Pauling, who was a friend to Jay Patrick and lived to the age of 93 is said to have thought that everyone would benefit from taking a few grams daily.

To assess your own needs, consult with your doctor or naturopath. You should never make any changes to diet or medication without consulting a qualified health professional, especially if you are pregnant or nursing.


Balch, Phyllis A., CNC. Prescription for Nutritional Healing: A Practical A-to-Z Reference to Drug-free Remedies Using Vitamins, Minerals, Herbs & Food Supplements, Fourth Edition, New York: Avery, 2006.

Davis, Martha, Ph.D., Robbins Eschelman, Elizabeth, MSW and McKay, Matthew, PhD. The Relaxation & Stress Reduction Workbook, fifth edition, Oakland: New Harbinger Publications, 2000.

O’Donnell, Tony, C.N.C., Naturopath, Miracle Super Foods that Heal, Burbank: O’Donnell, 2001.

Virtue, Doreen, PhD and Ross, Jenny, The Art of Raw Living Food, Carlsbad: Hay House, 2009.

Virtue, Doreen, PhD and Prelitz, Becky, M.F.T., R.D., Eating in the Light, Carlsbad: Hay House, 2001.

Reference Values for Vitamins,” Health Canada (accessed September 28, 2010).

Image: Jina Lee via Wikimedia Commons

Disclaimer: The information on this website is not intended to substitute advice from your physician or health-care professional. Before beginning any health or diet program, consult your physician.