Could Americans Be Deficient in Vitamin C?

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In a study of 15,769 children and adult, 14% of males and 10% of females were deficient in Vitamin C despite dietary and supplemental intakes that exceeded the Recommended Dietary Allownace. Furthermore, current smokers had the highest risk of vitamin c deficiency. 

Vitamin C deficiency, also known as scurvy, is usually only a topic for discussion in history classes, but what if it is being overlooked? Classic symptoms of scurvy include low-grade inflammation, fatigue, limping, bleeding gums, and swollen extremities (1).  Since these symptoms are common in many other conditions, especially autoimmune conditions, vitamin C deficiency is rarely screened for in patients (1).

The US Department of Agriculture surveyed food intakes in individuals and found that 18% of adults consumed less than 30 mg per day of vitamin C, indicating a risk for deficiency (2). Cigarette smokers are at an increased risk of vitamin C deficiency because vitamin C is depleted by free-radicals produced from smoking (1). Research has also shown that high intakes of vitamin C may decrease the risk of oral, esophageal, stomach and breast cancers (3).

To research this topic further, 15,769 children and adults (12-74 years) from the Third National Health and Nutrition Examination Survey were included in the study (1). Blood serum levels of vitamin C were collected, along with 24-hour dietary recalls and records of any supplements taken (1).

The following parameters were used, based on the blood serum levels of vitamin C:

– Deficiency: Less than 11 micromol/L
– Depletion: 11-28 micromol/L) 
– Normal: More than 28 micromol/L.

Despite dietary and supplemental intakes of vitamin C that exceeded the RDA (Recommended Dietary Allowance) in the test group, (145-210 mg per day), 14% of males and 10% of females were deficient in vitamin C (1).  Deficiency was greatest (17%) in 25-64 year old males and 25-44 year old females (12%) (1). Vitamin C depletion reached 23% in 25-44 year old males and 20% in 25-44 year old females (1).

Current smokers had the highest risk of vitamin C deficiency (males OR=3.6; 95% CI=3.2,3.4; females OR=4.2; 95% CI=3.6,4.9) (1). The Food and Nutrition Board of the National Academy of Sciences recommends that individuals who smoke consume an additional 35 mg of vitamin C per day (110-125 mg per day total) (1).

It is possible the deficiency in vitamin C is related to the poor consumption of nutrient dense foods. The leading fruits and vegetables consumed in the US in descending order are: iceburg lettuce, raw tomatoes, French fries, bananas and orange juice, making up almost 30% of all fruits and vegetables consumed. Broccoli, strawberries, kale and grapefruit — all rich sources of vitamin C — make up less than 2% of fruit and vegetable consumption in the US (4).

In conclusion, these nationwide data indicate a reasonable number of US citizens are vitamin C deficient or depleted (1). A healthy diet and supplementation should be considered, especially in those at greater risk for deficiency (smokers and poor eaters) (1). It is important to note that vitamin C is a water-soluble vitamin and therefore blood serum levels indicate only 1-4 weeks of vitamin C status, and therefore is a short-term view (1).

Abstracted by Jessica Patella, ND from “Vitamin C Deficiency and Depletion in the United States:  The Third National Health and Nutrition Examination Survey, 1988 to 1994.” in the 94th volume in 2004 of American Journal of Public Health. Posted June 21, 2012. r/mk

Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health.  Visit her website at  www.awarenesswellness.com.

References:

  1. Hampl J, et al. Vitamin C Deficiency and Depletion in the United States: The Third National Health and Nutrition Examination Survey, 1988 to 1994.  Am J of Public Health 2004; 94, 5: 870-875.
  2. Taylor CA, Hampl JS, Johnston CS. Low intakes of vegetables and fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults. Eur J Clin Nutr. 2000;54:573–578.
  3. Fairfield KM, Fletcher RH. Vitamins for chronic disease prevention in adults: scientific review. JAMA. 2002;287:3116–3126.
  4. Dickinson VA, Block G, Russek-Cohen E. Supplement use, other dietary and demographic variables, and serum vitamin C in NHANES II. J Am Coll Nutr.1994;13:22–32.

Nutritional Deficiencies, Tobacco, Vitamin C