The benefits of getting enough vitamin C are well known, especially for preventing the common cold. I should not be challenging to get enough vitamin C being we have access to fruits and vegetables year-round, but a recent study shows that many are not getting enough.
Researchers collected blood samples from 492 generally healthy, middle-class patients visiting a health care facility for routine health, gynecological and pregnancy exams. After evaluating vitamin C levels daily for 10 consecutive days, the researchers determined that 6.3% of the patients had vitamin C deficiency (less than half of the minimum recommended daily allowance, or RDA) and a whopping 30.4% had vitamin C depletion (barely the minimum RDA). 
|Table 1: Recommended Dietary Allowances (RDAs) for Vitamin C |
|0–6 months||40 mg*||40 mg*|
|7–12 months||50 mg*||50 mg*|
|1–3 years||15 mg||15 mg|
|4–8 years||25 mg||25 mg|
|9–13 years||45 mg||45 mg|
|14–18 years||75 mg||65 mg||80 mg||115 mg|
|19+ years||90 mg||75 mg||85 mg||120 mg|
|Smokers||Individuals who smoke require 35 mg/day
more vitamin C than nonsmokers.
* Adequate Intake (AI)
These rates are startling considering that a single piece of fruit (i.e., an orange) often provides a full day’s supply of vitamin C . Citrus fruits, tomatoes and tomato juice, and potatoes are major contributors of vitamin C to the American diet . Other food sources include red and green peppers, kiwifruit, broccoli, strawberries, brussels sprouts, and cabbage [2,4]. The vitamin C content of food may be reduced by prolonged storage and by cooking because ascorbic acid is water soluble and is destroyed by heat [2,3]. Many of the best food sources of vitamin C, such as fruits and vegetables, are usually consumed raw. Consuming five varied servings of fruits and vegetables a day can provide more than 200 mg of vitamin C. Make sure you stock your refrigerator with plenty of fruits and vegetables. If you are not meeting your nutritional needs with food supplementation of vitamin C can fill that gap. Remember to look to food first, then supplementation.
- Johnston CS, Thompson LL. Vitamin C status in an outpatient population. Journal of the American College of Nutrition, August 1998;17(4), pp366-70.
- Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000.
- Weinstein M, Babyn P, Zlotkin S. An orange a day keeps the doctor away: scurvy in the year 2000. Pediatrics 2001;108:E55. [PubMed abstract]
- U.S. Department of Agriculture, Agricultural Research Service. 2011. USDA National Nutrient Database for Standard Reference, Release 24. Nutrient Data Laboratory Home Page, http://www.ars.usda.gov/ba/bhnrc/ndl.
by Melanie Dockter, DC, CACCP