Lau Hui Ling
PhD, MPharm, RPh
Vitamin C (also known as ascorbic acid) is a vital water-soluble micronutrient which is known to have antioxidant properties that can aid in maintaining healthy skin, blood vessels, immune system, soft tissues and wound healing. A healthy, non-smoking adult requires approximately 75 – 90 mg (more in smoking adults) of vitamin C daily, something which is obtainable through a well-balanced diet. It is found abundantly in fruits (orange, watermelon, kiwi), berries (camu camu, acerola berries and blueberries) as well as vegetables such as green peppers, broccoli and tomatoes. However, when vegetables are washed and cooked, part of its vitamin C content may be lost in the process.
While it is a common perception that supplements containing naturally-sourced vitamin C are better than its synthetic counterparts, this however is untrue. In fact, most vitamin C supplements in the market contain either synthetic ascorbic acid, mineral ascorbates or processed fruit and berry extracts. Synthetic vitamin C and natural vitamin C are not known to be of any difference in terms of its molecular structure: the L-ascorbic acid found in a kiwi is the same as that found in a common vitamin C supplement tablet.
A research conducted in 2013 did not find any significant differences in the amount of vitamin C measured in body fluids and tissues between people who consumed either synthetic vitamin C or kiwi fruit-derived vitamin C. Furthermore, other studies have shown negligible differences in vitamin C absorption whether it is given as a synthetic vitamin C tablet, orange juice or cooked broccoli.
Vitamin C in food source is usually present with a number of flavonoids such as rutin and hesperidin. Although many believe that vitamin C is better absorbed in the presence of these flavonoids, most studies at present reported negligible difference in absorption when vitamin C was given with or without flavonoids.
While a majority of us would obtain sufficient vitamin C from a well-balanced diet, individuals such as chronic smokers, people who are continuously exposed to second-hand smoke, people who consume very limited variety of food, people who suffer from malabsorption, or kidney disease requiring hemodialysis may require daily vitamin C supplementation.
To date, there has been no compelling evidence of superior effectiveness of natural vitamin C over synthetic vitamin C or vice versa. Therefore, the choice of supplementing with either naturally-sourced vitamin C or synthetic vitamin C should be based on one’s preference. Speak to your pharmacist to know more about the types of supplements available to meet your needs!
Stay tuned for our next article which compares the absorption from powder, effervescent, oral or chewable tablet and slow release preparations.
- Carr, A.C., Vissers, M.C.M. (2013) Synthetic of Food Derived Vitamin C – Are They Equally Bioavailable? Nutrients. 5(11): 4084 – 4304. Accessible at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3847730/
- Factsheet: Vitamin C. National Institutes of Health. Office of Dietary Supplements. Updated June 2011. Accessible at: https://ods.od.nih.gov/factsheets/VitaminC-Consumer/
- Mangel, A.R., Block, G., Frey, C.M., et al. (1993) The Bioavailability to Humans of Ascorbic Acid from Oranges, Orange Juice and Cooked Broccoli is Similar to That of Synthetic Ascorbic Acid. Human and Clinical Nutrition. 1054 – 61.
- Carr, A.C., Bozonet, S.M., Pullar, J.M., et al. (2013) A Randomized Steady-State Bioavailability Study of Synthetic versus Natural (Kiwifruit-derived) Vitamin C. Nutrients. 5: 3684 – 95. Accessible at : http://www.mdpi.com/2072-6643/5/9/3684
- Vallejo, F., Tomás – Barberán, F.A., García – Viguera, C. (2002) Glucosinolates and Vitamin C Content in Edible Parts of Broccoli Florets after Domestic Cooking. Eur Food Res Technol. 215: 310-316.