Vitamin C, also called ascorbic acid, is a water-soluble nutrient that your body can easily excrete when it’s not needed. Vitamin C hydrates your body and increases your metabolism, leading to weight loss and healthy blood sugar levels. It is necessary for the formation of bones, muscles, blood vessels and other supporting cells and tissues. In fact, vitamin C so critical that almost all animals can make it in their cells. Higher-order primates (including humans), guinea pigs, most bats, and some birds and fish are some of the few animals that cannot synthesize vitamin C and need to consume it in their daily diets.

Vitamin C can:

• Support strong cells and tissues: Your body uses vitamin C to produce collagen. Without vitamin C, your bones, muscles, blood vessels, gums, mucous membranes, corneas, joints, and other supporting cells and tissues would too unstable to perform their functions, and you would develop symptoms of scurvy. Scurvy leads to the formation of brown spots on the the skin (especially on the thighs and legs), spongy gums, and bleeding from all mucous membranes. People with scurvy look pale, feel depressed, and are partially immobilized. In advanced scurvy there are open, puss-oozing wounds, loss of teeth, and eventually, death. Nobel prize winners Linus Pauling and G. C. Willis have asserted that chronic, long-term, low blood levels of vitamin C (“chronic scurvy”) is a cause of atherosclerosis (hardening of the arteries). Vitamin C also helps relieve stiff joints and promotes wound healing.
• Help protect cells from free radical damage: Vitamin C protects your body by functioning as an antioxidant and preventing oxygen-based damage to your cells. It acts primarily in cellular fluid, combating free-radical formation caused by pollution and cigarette smoke. It also helps return vitamin E to its active form. Structures that contain fat (like the lipoprotein molecules that carry fat around your body) are particularly dependent on vitamin C for protection. In addition, vitamin C boosts your body’s production of glutathione, a powerful antioxidant.
• Lower your cancer risk: Antioxidants such as vitamin C help prevent cancer growth by neutralizing volatile oxygen free radical molecules and preventing damage to your DNA that can lead to cancer. Vitamin C also destabilizes a tumor’s ability to grow under oxygen-starved conditions. Many studies have correlated high vitamin C intakes with low rates of cancer, particularly cancers of the mouth, larynx and esophagus.
• Regenerate your vitamin E supplies: Although vitamin E is an antioxidant, it can become oxidized when it interacts with a free radical, therefore creating more oxidative damage. But vitamin C can interact with oxidized vitamin E, reducing free radicals and regenerating the benefits of vitamin E.
• Improve iron and calcium absorption: Vitamin C binds with plant forms of iron, increasing its stability and solubility and helping to transport it to your intestines so it can be absorbed. Non-heme iron combined with ascorbic acid is more readily absorbed through the mucus membranes of your intestines. Calcium needs an acidic environment for absorption, and the presence of ascorbic acid helps it to be absorbed.
• Support your immune system: A strong immune system is vital in preventing all kinds of diseases, from the common cold to cancers and cardiovascular diseases. Your immune system relies on a wide variety of mechanisms to help protect your body from infection, including white blood cells, complement proteins, and interferons, and vitamin C is especially important in the function of these immune components. Vitamin C boosts your body’s production of gultathione, a powerful antioxidant that also helps create lymphocytes, the cells of your immune system, which keep your body’s defenses strong and produce antibodies. Vitamin C protects your phagocytes and T-lymphocytes against free radicals formed during the interaction of these immune system cells with harmful microorganisms. The T-cells and other phagocytes engulf the microorganisms and use oxygen in the form of superoxides to destroy them. These superoxides can be harmful to the phagocytes themselves. Vitamin C protects them against the free radicals and thereby maintains the integrity of these cells. A deficiency of vitamin C hampers this immune function and results in early destruction of the T-cells and phagocytes. Vitamin C decreases the duration of the common cold and helps prevent lung infections.
• Eliminate toxins: Vitamin C is critical during the first phase of your body’s detoxification process, which occurs in many types of tissue, but it is especially active in your liver. When your body is exposed to toxins, vitamin C is often required for your body to begin processing the toxins for elimination. Vitamin C boosts your body’s production of gultathione, a powerful antioxidant that also helps your liver eliminate toxins.
• Act as an antihistamine: Vitamin C prevents histamine release and increases the detoxification of histamine.

Scurvy had long been the prime killer of sailors during long sea voyages that left them without access to fresh vegetables and fruit. Their body stores of vitamin C fell below 300 milligrams, and their gums and skin lost the protective effects of vitamin C.  In the 1770s, Captain James Cook had his sailors eat limes, lemons, and sprouts; all abundant sources of vitamin C. By 1795, the British navy was obtaining limes from the British West Indian colonies, and made them standard issue at sea to prevent scurvy. This practice led to the American use of the nickname “limey” to refer to the British.

Full-blown scurvy is rare in the U.S., but common symptoms associated with vitamin C deficiency include:

• Poor wound healing
• Weak immune function, including susceptibility to colds and other infections
• Respiratory infection and other lung-related conditions can also be symptoms of vitamin C deficiency

Factors that lead to vitamin C deficiency include:

• Poor intake of vitamin C-rich vegetables and fruits: In the U.S., one third of all adults get less vitamin C from their diet than is recommended by the National Academy of Sciences, and 1 out of every 6 adults gets less than half the amount recommended.
• Smoking and exposure to second hand smoke.
• Excessive toxic exposure. 

Vitamin C from food is non-toxic. High supplemental doses (5 or more grams) of vitamin C can cause diarrhea. Vitamin C can also increase your absorption of iron from plant foods, so if you have health problems related to excess free iron in your cells, you may want to avoid high supplemental doses of vitamin C. In 2000, the National Academy of Sciences set a Tolerable Upper Intake Level (UL) for vitamin C at 2,000 milligrams (2 grams) for adults 19 years or older.

Vitamin C interacts with several other nutrients in your body. In addition to enhancing iron absorption, vitamin E regeneration, and glutathione production, supplemental intake of vitamin C at gram-level doses can interfere with copper metabolism. Rutin, found in apricots, buckwheat, cherries, prunes, rose hips, the rind of citrus fruits, and the core of green peppers, helps your body use vitamin C and maintain collagen. Hesperidin, found in lemons, oranges, grapefruit, tangerines, apricots, plums, bilberry, green and yellow peppers, broccoli, and whole grains, works together with vitamin C to maintain healthy collagen, which prevents sagging and wrinkling of the skin.

Vitamin C is highly sensitive to air, water, and temperature. You can lose about 25% of the vitamin C in vegetables simply by steaming the food for a few minutes. You can lose the same amount by freezing and thawing vegetables and fruits. Cooking vegetables and fruits for longer periods of time (10-20 minutes) can result in a loss of over one half the total vitamin C content. When fruits and vegetables are canned and then reheated, only 1/3 of the original vitamin C content may be left. Consuming vitamin C-rich foods in their fresh, raw form is the best way to maximize vitamin C intake. In general, an unripe food is much lower in vitamin C than a ripe one, but provided that the food is ripe, the vitamin C content is higher when the food is younger at the time of harvest.

Excellent food sources of vitamin C include papaya, bell peppers, strawberries, broccoli, pineapple, Brussels sprouts, kiwifruit, oranges, cantaloupe,  kale, cauliflower, starfruit, bok choy, grapefruit, turnip greens, mustard greens, collard greens, raspberries, chard, napa cabbage, lemon and lime juice, cabbage, tomatoes, Romaine lettuce, sweet potato, winter squash, green peas, summer squash, spinach, potatoes, yams, avocados, watercress, blueberries, basil, watermelon, and green beans.

Sources of Vitamin C

This blog uses the latest nutritional data available from the USDA (United States Department of Agriculture), and the FDA (United States Food and Drug Administration), as well as nutritional data provided by food growers and manufacturers about their products. We believe the information on this website to be accurate. However, we are not responsible for typographical or other errors. Nutrition information for recipes is calculated by Living Cookbook based on the ingredients in each recipe based on statistical averages. Nutrition may vary based on methods of preparation, origin and freshness of ingredients, and other factors.

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