Vitamin C

Vitamin C has many functions including:

  • Prevention of scurvy (vitamin C deficiency). Symptoms include bleeding gums, fatigue, muscle weakness, unhealed wounds, nosebleeds and bruising.
  • Formation of collagen (cementing protein that holds cells together) needed for strengthening bones, teeth, skin and blood vessels.
  • Wound healing and protection from infections and bruising (immunity).
  • Production of amino acids (makes proteins), hormones, hemoglobin (carries oxygen in red blood cells) and neurotransmitters (brain's chemical messengers).
  • Metabolism of folic acid (B-vitamin).
  • Increased absorption of iron from plant-based foods (e.g., cereal, bread).
  • Antioxidant (neutralizes "free radicals" that damage cells) that may reduce risk for cancer (e.g., gastrointestinal, lung, cervix), heart and eye diseases, strokes and other diseases. May reduce asthma symptoms (prevents lung damage).
  • Enhancement of action of other antioxidants such as vitamin E.

Food sources: The best food sources for vitamin C are fruits (especially citrus and tropical varieties), vegetables and juices.

Examples include oranges, grapefruits, lemons, limes, strawberries, kiwifruit, melons, mangoes, peppers (red and green), cabbage, tomatoes, potatoes, cauliflower and dark green, leafy vegetables (see chart on this page). Apples (and bananas) are not rich in vitamin C, so serve vitamin C-fortified apple juices.

Fresh-squeezed orange juice usually contains more vitamin C than frozen or canned. But, vitamin C content of all juices declines with time (about 50% in one month) and exposure to air (juice in cartons loses vitamin C). Keep juices refrigerated in tightly closed glass containers, and use quickly.

How much: In 2001, the Daily Reference Intake for vitamin C was increased to 75 mg./day for women and 90 mg./day for men. For smokers, an additional 35 mg./day is advised.

The optimal intake is still unknown. The amount needed to saturate tissues and help prevent diseases (especially in the elderly) is higher than the DRI—about 200 mg. /day.

However, food sources (at least five servings of fruits and vegetables daily) are recommended rather than supplements. These foods also provide fiber, other nutrients (e.g., potassium and beta carotene) and phytochemicals (plant substances) that may interact with vitamin C to reduce risk of chronic diseases.

Possible toxicity: Excess vitamin C from supplements can lead to diarrhea, kidney stones, infections, blood clotting or nutrient deficiencies (e.g., copper). Over 500 mg./day may not be well absorbed. The "Tolerable Upper Intake Level" (UL) is 2,000 mg./day for adults.

Disease prevention: Several large-scale studies are currently investigating how and if antioxidants like vitamin C reduce risk for chronic diseases. Preliminary research with supplements has been inconsistent and disappointing. Here's a summary of some recent findings:

Heart Disease—Vitamin C may slow or prevent the oxidation of "bad" LDL-cholesterol in blood to prevent plaque build-up in arteries. Vitamin C may also increase nitric oxide production which dilates arteries allowing blood to flow freely (prevents clots). Vitamin C may boost "good" HDL-cholesterol (protective) and reduce blood pressure by dilating blood vessels.

Stroke—Men with the lowest blood levels of vitamin C had more than double the risk of stroke (blood clot in the brain) as men with the highest levels.

Cancer—Vitamin C may mop up free radicals, detoxify carcinogens (cancer-causing agents) and boost immunity. Vitamin C may also inhibit growth of H. pylori (bacteria) which causes ulcers and increases risk of stomach cancer. In the stomach, vitamin C can block formation of nitrosamines (carcinogens) from nitrites and nitrates (found in vegetables and salt-cured foods like hotdogs and cold cuts). Nitrosamines may increase risk of stomach cancer.

Eye diseases—Some people taking vitamin C supplements had lower risk of cataracts. For elderly who already had age-related macular degeneration (ARMD), which can cause blindness, supplements containing vitamin C (and other antioxidants like vitamin E plus zinc and copper) slowed the progression of ARMD, but did not lower cataract risk.

Colds—High doses of vitamin C do not prevent colds. In some studies, vitamin C supplements reduced the severity and duration of a cold, but only slightly.

Gallbladder disease—Bile (stored in the gallbladder to help digest fat) is made from cholesterol. Vitamin C helps convert cholesterol into bile to prevent formation of gallstones from cholesterol. In one study, women with high blood levels of vitamin C had less gallbladder disease than women with low levels.

No such connection was seen in men, but they have a lower incidence of gallbladder disease. In another study, postmenopausal women taking vitamin C supplements also developed less gallbladder disease.

Brain diseases—Supplements of antioxidants like vitamins C and E may prevent or slow the progression of Alzheimer's and Parkinson's diseases. In one study, supplements were also associated with less dementia and memory loss in the elderly.

More From FoodService Director

Sponsored Content
boston college acai bowl

From Dannon Foodservice.

Catering to the go-go-go lifestyle of university students is a challenge, and it’s one that Boston College dining representatives wrestle with daily.

“Students don’t just want to eat dinner between 5 and 7 p.m.,” says Beth Emery, the school’s director of dining. “They may want to eat dinner at 9 o’clock. We’ve been trying to come up with creative solutions.”

Those creative solutions include everything from offering breakfast items throughout the day to providing healthier late-night choices to trolling social media for trendy new menu ideas...

Sponsored Content
savory yogurt parfait

From Dannon Foodservice.

What consumers eat and, most importantly, when they’re eating it has changed significantly in recent years, signaling opportunity for operators able to capitalize on this evolution.

For example, some 83% of consumers said they were daily snackers in 2016, according to Technomic’s Snacking Occasion Consumer Trend Report . That’s up from 76% just two years earlier. Snacking is growing across many channels from retail prepared foods to bakery and coffee cafes, fast-food locations and more.

Busy lifestyles, smaller households with greater meal...

Industry News & Opinion

Labor secretary nominee Andy Puzder has officially bowed out of consideration for the cabinet position, according to the Associated Press .

Puzder, CEO of CKE Restaurants—the parent company of Hardee’s and Carl’s Jr.—was tired of being under fire for hiring an undocumented immigrant as a nanny and being accused 26 years ago of physically abusing his wife, an unnamed source told CBS News . The agency reported that Puzder was unlikely to show for the start of his confirmation hearings tomorrow.

Puzder has also been attacked by organized labor for comments suggesting that...

Industry News & Opinion

Risley Dining Room at Cornell University in Ithaca, N.Y., has just become 100 percent gluten-free, 14850.com reports.

For the past two years, the university has slowly phased out gluten in the dining hall’s menu by eliminating it in its stir fries, biscuits and brownies.

Instead of offering gluten-free versions of typical college fare, including pizza and pasta, the dining service team aimed for more sophisticated restaurant-style items.

Along with being gluten-free, Risley is also peanut free and tree-nut free.

The dining room is the second college eatery...

FSD Resources