Are You Consuming Enough Vitamin C? Probably Not 17 Jul 2012
Almost 400 years ago, surgeon John Woodall recommended the preventative and curative powers of lemon juice. In 1747, British Royal Navy Surgeon James Lind, conducted a controlled experiment to demonstrate that citrus fruit prevented scurvy which was published in his ‘Treatise on the Scurvy’ in 1753. Based partly on these findings, the vitamin C recommended dietary allowance (RDA) was set to prevent scurvy, the vitamin C deficiency disease.
In 2012, Frei and colleagues question whether most people are consuming enough vitamin C? The answer is no. They review the scientific evidence and conclude that 200 mg per day is optimal for the majority of the population. This intake will maintain plasma vitamin C concentrations above 70 μM. 60-100μM is the concentration required for maximal transport by the vitamin C transporter (SVCT2) in humans to saturate cells, and presumably tissues.
As stated by Dr Balz Frei in ScienceDaily, “Significant numbers of people in the U.S. and around the world are deficient in vitamin C, and there’s growing evidence that more of this vitamin could help prevent chronic disease.”
Although it is difficult to believe, 6% of Americans over 5 years are vitamin C deficient (< 11.6μM) according to CDC 2nd Nutrition Study and the majority have vitamin C concentrations <70μM. In adequate vitamin C concentrations reflect the fact that most people are not eating the recommended 5 to 9 servings of fruit and vegetables daily. Indeed, many children do not meet WHO recommendations for 400 grams of fruit and vegetables daily. And there is evidence that fruit and vegetable consumption among 11 year old children in the Netherlands declined between 2003 and 2009.
Bottomline: Almost everyone can benefit from eating more fruit and vegetables. The USDA National Nutrient Dabase (SR 24) lists vitamin C content of selected foods. The Office of Dietary Supplements National Institutes of Health has Vitamin C resources. -mm-
Frei B, Birlouez-Aragon I, Lykkesfeldt J. Authors’ Perspective: What is the optimum intake of vitamin C in humans? 2012 Crit Rev Food Sci and Nutr 52:815.