Vitamin C must be obtained either through diet or supplementation as unlike most animals and plants, humans have lost the ability to synthesize this nutrient. Vitamin C is water-soluble which means that only a certain amount is used and can’t be stored. Given that any excess is excreted, continually restoring vitamin C is required to ensure adequate intake.
Vitamin C is an essential component of collagen, the most abundant protein in the body that is essential for building new bone, cartilage, tendon, skin and other connective tissue. As a result, vitamin C plays an important role in wound healing by supporting the development of new tissue and blood vessels.
Vitamin C works as an antioxidant to quench free-radicals in the aqueous or watery part of cells. It also regenerates other antioxidants and works in concert with vitamin E (which works in lipid environments).
Vitamin C may play a role in the prevention and treatment of cancer, cardiovascular disease, age-related macular degeneration (AMD) and cataracts and the common cold. Epidemiological studies suggest that high intakes of fruits and vegetables are associated with lower risk of most types of cancer and reduced risk of cardiovascular disease. However, the evidence is inconsistent whether dietary vitamin C intake affects cancer risk or reduces cardiovascular disease morbidity or mortality. Studies indicate that vitamin C may slow the progression of AMD and higher intakes may reduce the risk of developing cataracts.
Under certain conditions, the requirement for vitamin C is increased. Smokers, those exposed to second hand smoke, older persons and those under stress have a greater need for this vitamin.
Major Functions of Vitamin C
– An antioxidant needed for tissue growth and repair, adrenal gland function and healthy gums
– Plays a primary role in the formation of collagen
– Promotes the healing of wounds, protects against blood clotting and bruising
– Involved in immune health
– Enhances body’s absorption of iron
Any food that contains vitamin C also contains bioflavonoids. Bioflavonoids are required for absorption of vitamin C and both work together in the body. Although bioflavonoids are not considered a vitamin, they are sometimes referred to as vitamin P.
Bioflavonoids are found abundant in citrus fruit rinds and pulp. Common bioflavonoids include citrus flavonoids found in citrus fruits; rutin in buckwheat; epigallocatechin gallate (EGCG) in green tea; anthocyanidins in bilberry; naringenin in grapefruit; oligomeric proanthocyanidins in grape seeds and skins and quercetin in onions, tea, and apples.
Fruits and vegetables are the best sources of vitamin C. With 2,000 mg/100 grams, rose hips have one of the highest concentrations of vitamin C. Other plants that are good sources include peppers (red pepper, hot chillis); berries (black currant, loganberry, elderberry, goji, cloudberry, strawberry, raspberry, blackberry, cranberry); citrus fruits (orange, lemon, grapefruit, tangerine, lime); green vegetables (parsley, broccoli, Brussels sprouts, kale, spinach) and other fruits (guava, kiwifruit, papaya, melon).
The vitamin C content of foods is reduced with cooking, freezing and then unthawing. Higher temperatures and longer cooking times magnify this effect. Fresh cut fruits do not lose significant vitamin content when stored in the refrigerator for a few days. Eating fruits and vegetables at their peak ripeness in their raw state is the best way to maximize vitamin C intake.
Recommended Dietary Allowance
The Recommended Dietary Allowance (RDA) for vitamin C for adult men is 90 mg and for adult women is 75 mg. Vitamin C has low toxicity and is not believed to cause serious adverse effects even at high intakes. For adults, the Tolerable Upper Intake Level for vitamin C is 2,000 mg. An RDA does not exist for bioflavonoids.
If you look on a nutritional supplement facts panel, you’ll notice the Amount Per Serving for vitamin C and the % Daily Values is at located at the top of the panel. The Amount Per Serving is based on the Reference Daily Intake (RDI) for this nutrient which is considered to be sufficient to meet the requirements of nearly all (97–98%) healthy individuals in each life-stage and sex group. The Reference Daily Intake for vitamin C is 60 mg which represents 100% of the Daily Values.
Keep in mind, that the Daily Values is the amount considered sufficient to prevent disease (e.g., scurvy which was prevalent amongst sailors up until the 18th century). Many studies indicate that higher amounts of vitamin C are required to enhance immunity and provide other health benefits.
The amount of vitamin C in the body tissues is tightly controlled. At moderate intakes (30 – 180 mg a day), 70 to 90 percent of vitamin C is absorbed. But, at doses above 1 gram, absorption falls to less than 50 percent. For this reason, taking reasonable amounts of vitamin C (150 mg) in divided doses ensures optimal absorption of this nutrient.
Certain drugs can reduce the body’s supply of vitamin C including birth control pills, non-steroidal anti-inflammatory drugs (e.g., Advil), corticosteroids, sulfa drugs and barbiturates.
Given the role of vitamin C in developing new tissue and wound healing, it’s not surprising that this nutrient is featured in our Recovery Product line. Both the Recovery Support Program and Clinical Support Program are formulated with 750 mg of vitamin C. To optimize absorption, 375 mg is provided in both the morning and evening formulation. Additionally, these products are formulated with 600 mg of bioflavonoids to enhance absorption and assimilation of this nutrient.
Compared with our everyday supplements, the amount of vitamin C and bioflavonoids is higher in our Recovery products. That’s because the body’s requirements for these nutrients is much higher following the stress of surgery, the level of oxidation generated by anesthesia & narcotics and the importance to building new tissue.
Many of our Wellness Products are formulated with vitamin C at reasonable amounts, in divided doses. As an example, our Multi-Vitamin & Mineral and Anti-Aging Formula provide 300 mg daily of vitamin C, divided in a 150 mg morning and 150 mg evening dose. These products are also formulated with bioflavonoids to enhance absorption.
Last updated July 1, 2018
David H. Rahm, M.D. is the founder and medical director of The Wellness Center, a medical clinic located in Long Beach, CA. Dr. Rahm is also president and medical director of VitaMedica. Dr. Rahm is one of a select group of conventional medical doctors who have education and expertise in functional medicine and nutritional science. Over the past 20 years, Dr. Rahm has published articles in the plastic surgery literature and educated physicians about the importance of good peri-operative nutrition.