Vitamin C: Essential Protection for the Winter and Beyond
In an era of astounding scientific breakthroughs—where healthy babies are crafted from the genes of three parents and we use CT scans to analyze 99- million-year-old baby bird hatchlings preserved in amber—we can sometimes forget the simple things. That includes the well-known goodness of vitamin C, famous for preventing the fatal disease scurvy in 18th century sailors and for winning the unbridled enthusiasm of two-time Nobel winner Linus Pauling.
Vitamin C—also known as ascorbic acid—is one of those essential nutrients that we cannot synthesize ourselves. It is a water soluble molecule and must be obtained from our diet or from supplements. It is absorbed in our small intestine about 2-3 hours after we consume it, and distributed from the blood through the entire extracellular space, though it is most highly concentrated in the liver, brain and skeletal muscle.1 Vitamin C has been shown to be important in immune function, wound healing, mood, allergies, and more.2,3,4
Vitamin C works its magic as an “electron donor”—when it donates electrons, it offers energy to fifteen different enzymes that are crucial for many functions in mammals.5 When an oxidized molecule gains an electron, it not only gains energy—it is then stabilized and called “reduced.” By donating electrons to oxidized molecules, vitamin C can function as a powerful antioxidant.6 In fact, vitamin C is one of the most potent water-soluble antioxidants in the body.7 The vitamin not only scavenges free radicals, it also reduces lipid peroxidation of cellular membranes, and supports other important antioxidants, including vitamin E and glutathione.8,9 It is essential for collagen synthesis, as well as the synthesis of carnitine and important neurotransmitters.10
You might think you get enough vitamin C from your diet—after all, it is abundant in foods ranging from strawberries to oranges, grapefruits, papaya, broccoli, kale and more. However, low dietary intake and plasma concentrations of the vitamin are surprisingly common. One survey of over 7,000 Americans found that 8.2% of males and 6% of females had such low concentrations of vitamin C in their blood they could actually experience symptoms of scurvy.11 In addition, the vitamin is depleted by smoking, serious illness, and heart attacks.12,13
Increasing our vitamin C intake can have many beneficial effects. The vitamin can help prevent, as well as decrease the severity of infections, particularly the common cold. Vitamin C along with zinc has been shown to reduce symptoms of the common cold over a five day period.14 Nearly 150 animal studies have shown that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. It has been shown to reduce the number of colds in physically active people by half, and shorten the duration of colds as well; also helping to prevent pneumonia in two studies.15 In addition, case reports suggest it may help ameliorate outbreaks of herpes zoster (commonly called shingles), as well as reduce the painful neuralgia associated with it.16,17
Vitamin C can improve the function of the immune system’s first line of defense, natural killer cells.18 Neutrophils, which when activated produce oxidants such as ozone and hydrogen peroxide that kill pathogenic bacteria, rapidly absorb vitamin C, increasing their concentrations as much as ten times.19
Vitamin C may be necessary for a healthy response to stress. It is necessary to help our adrenal glands synthesize several hormones and neurotransmitters. In fact, the adrenals are one of the organs with the highest concentration of vitamin C, and they actually secrete the vitamin in response to the stress hormone, adrenocorticotrophic hormone (ACTH).20
Stress can impact mood, so it’s not surprising to learn that vitamin C is also important in balancing mood. The vitamin enhances the production of the feel-good, energizing neurotransmitter norepinephrine.21 Deficiency of vitamin C has been linked to lower levels of metabolites of two major mood-enhancing neurotransmitters, dopamine and serotonin.22 Low plasma ascorbic acid levels correlate with major depression.23 Vitamin C also appears to reduce anxiety and depression in double-blind, randomized, placebo-controlled trials.24,25 The vitamin has even been shown to improve mood in hospitalized patients.26
When we take conventional vitamin C by mouth as a supplement, absorption actually decreases with increasing dosage due to gastrointestinal saturation. A liposomal delivery form can circumvent that loss and enable effective high-level dosing without intravenous therapy.27,28 In addition, sodium ascorbate, a mineral salt of ascorbic acid, is buffered and generally better tolerated than regular ascorbic acid supplements by those with gastrointestinal sensitivity.
Vitamin C’s diverse benefits show just how versatile and fundamental this simple, water-soluble molecule really is. As an electron donor, vitamin C is essential to the exchange of energy throughout your body. It is also necessary for recycling and recharging other antioxidants to control free radical damage. No wonder it impacts everything from your immune system to your mood.
1 Padayatty SJ, Levine M. Vitamin C physiology: the known and the unknown and Goldilocks.
Oral Dis. 2016 Sep;22(6):463-93. View Full Paper
3 Hagel AF, Layritz CM. Intravenous infusion of ascorbic acid decreases serum histamine concentrations in patients with allergic and non-allergic diseases. Naunyn Schmiedebergs Arch Pharmacol. 2013 Sep
1;386(9):789-93. View Abstract
5 Stone, I. The Natural History of Ascorbic Acid in the Evolution of the Mammals and Primates and Its Significance for Present Day Man. 1956 [Cited Nov 10, 2017] Available at: https://www.seanet.com/~alexs/.../stone-i-orthomol_psych-1972-v1-n2-3-p82.htm
8 Machlin LJ, Bendich A. Free radical tissue damage: protective role of antioxidant nutrients.
FASEB J. 1987 Dec;1(6):441-5 View Full Paper
9 Meister A. Glutathione-ascorbic acid antioxidant system in animals. J Biol Chem. 1994 Apr
1;269(13):9397-400. View Full Paper
11 Schleicher RL, Carroll MD, Ford ES et al. Serum vitamin C and the prevalence of vitamin C deficiency in the United States: 2003-2004 National Health and Nutrition Examination Survey (NHANES). Am J Clin Nutr. 2009 Nov;90(5):1252-63. View Abstract
13 Padayatty SJ, Levine M. Vitamin C and myocardial infarction: the heart of the matter.
Am J Clin Nutr. 2000 May;71(5):1027-8 View Full Paper
14 Maggini S, Beveridge S, Suter M. A combination of high-dose vitamin C plus zinc for the common cold.
Int Med Res. 2012;40(1):28-42. View Full Paper
18 Huijskens MJ, Walczak M, Sarkar S et al. Ascorbic acid promotes proliferation of natural killer cell populations in culture systems applicable for natural killer cell therapy. Cytotherapy. 2015 May;17(5):613-20 View Abstract
23 Khanzode SD, et al. Oxidative damage and major depression: the potential antioxidant action of
selective serotonin re-uptake inhibitors. Redox Rep. 2003;8(6):365-70. View Abstract
24 de Oliveira IJ. Effects of Oral Vitamin C Supplementation on Anxiety in Students: A Double-Blind,
Randomized, Placebo-Controlled Trial. Pak J Biol Sci. 2015 Jan;18(1):11-8. View Abstract
25 Amr M. Efficacy of vitamin C as an adjunct to fluoxetine therapy in pediatric major depressive
disorder: a randomized, double-blind, placebo-controlled pilot study. Nutr J. 2013 Mar;12(1):1. View Full Paper
26 Zhang M, Robitaille L, Eintracht S et al. Vitamin C provision improves mood in acutely hospitalized
patients. Nutrition 2011, 27, 530–533. View Abstract