This post is going to be long so buckle up. Let’s dive into the world of Vitamin C.
While I don’t want to go in depths behind the molecular science behind the utilisation and processes in the skin anatomy with respect to Vitamin C, it is crucial to superficially understand everything.
Vitamin C is an essential vitamin, that human body (and some other mammals) cannot produce by itself, unlike most other animals. Our body cannot make it’s own Vitamin C because of the lack of L-gulonolactone oxidase enzyme, although it plays a crucial role in our existence. Vitamin C refers to ascorbic acid and dehydroascorbic acid as both help to treat scurvy, a classical condition caused by the deficiency of Vitamin C.
Some abstracted applications from this journal:
Vitamin C is a potent antioxidant capable of neutralizing oxidative stress through an electron donation/transfer process.
Vitamin C favours the absorption of iron, calcium and folic acid, which prevents allergic reactions and a decrease in the intracellular content of Vit C can lead to immunosuppression. Therefore, Vit C supplementation is recommended during infection and stress.
Vit C stimulates the formation of bile in the gallbladder and facilitates the excretion of steroid hormones.
Vitamin C acts directly on collagen biosynthesis and is an enzymatic cofactor for lysyl and prolyl hydroxylases, key enzymes for the stabilization and cross-linking of type I and III collagen fibres. It also plays an important role in the intracellular signalling cascade that leads to fibroblast proliferation.
Vitamin C could selectively kill cancer cells by inducing H2O2 production. However, this theory is still controversial in the scientific community.
Vitamin C also appears to exert important brain functions that go well beyond its antioxidant activity. It acts as an enzymatic cofactor in the biosynthesis of collagen, carnitine, tyrosine and peptide hormones. It stimulates myelin production, maturation and differentiation of neurons. Studies show that Vitamin C deficiency is a common factor in the development of neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, multiple sclerosis and amyotrophic sclerosis, as well as psychiatric disorders including depression, anxiety and schizophrenia.
All along my mother has been accurate. Clearly, vitamin c is essential.
While researching I felt it’s important to explore more in-depth about its antioxidant properties. This part will focus on oxidation as a process. If you understand what oxidation means, skip this part.
Vitamin C is a powerful antioxidant. It has been hypothesised to reduce damage caused by ROS by diminishing the oxidative stress.
Oxidation is a chemical reaction caused by reactive oxygen species (ROS), commonly known as free radicals. ROS are produced as a consequence of endogenous (normal metabolic process) and exogenous (smoking, pollution, UV, stress, etc.) factors. Routinely our body is able to control this in a complex process using the antioxidants bank in our body that helps to manage the free radical damage. However, if there is a disproportion between free radicals and the antioxidants in the body, the body is under oxidative stress.
I found that this video explains the oxidation process and role of antioxidants at the molecular level in detail. I highly recommend you to check out this video to understand the process & it’s implications.
Here are some medical articles that can help you understand more about oxidation:
Antioxidant and Oxidative Stress: A Mutual Interplay in Age-Related Diseases
Oxidative stress, ageing, and diseases
Oxidative Stress: Harms and Benefits for Human Health
A few relevant excerpts from these articles:
Free radicals are generated from both endogenous and exogenous sources. Immune cell activation, inflammation, ischemia, infection, cancer, excessive exercise, mental stress, and aging are all responsible for endogenous free radical production. Exogenous free radical production can occur as a result from exposure to environmental pollutants, heavy metals (Cd, Hg, Pb, Fe, and As), certain drugs (cyclosporine, tacrolimus, gentamycin, and bleomycin), chemical solvents, cooking (smoked meat, used oil, and fat), cigarette smoke, alcohol, and radiations [15–25]. When these exogenous compounds penetrate the body, they are degraded or metabolized, and free radicals are generated as by-products.
If in excess, free radicals and oxidants give rise to a phenomenon known as oxidative stress; this is a harmful process that can negatively affect several cellular structures, such as membranes, lipids, proteins, lipoproteins, and deoxyribonucleic acid (DNA) [16–21]. Oxidative stress emerges when an imbalance exists between free radical formation and the capability of cells to clear them.
Oxidative stress plays a crucial role in the development of age-related diseases including arthritis, diabetes, dementia, cancer, atherosclerosis, vascular diseases, obesity, osteoporosis, and metabolic syndromes (Tan et al., 2015a; Liu et al., 2017).
Data from both animal and population-based studies have shown that a correlation between the process of aging and reducing ascorbate levels in tissues (Michels and Hagen, 2004; Dixit et al., 2015). The mechanisms that implicate the declining of age-related ascorbate are complex and involve multiple cell signaling pathways such as accelerated turnover, increased usage, reduced cellular uptake, and decreased absorption/reabsorption.
ROS upregulate transcription factor activator protein-1 (AP-1). AP-1 increases matrix metalloproteinase (MMP) production resulting in collagen breakdown. Nuclear transcription factor kappa B (NF-κB) is also induced by oxidative stress and produces a number of inflammatory mediators that contribute to skin aging. Additionally, ROS increase elastin mRNA levels in dermal fibroblasts which may provide an explanation for the elastotic changes found in the photoaged dermis.
So in conclusion, Oxidation is a process linked to ageing. Excessive & prolonged oxidative stress can contribute to the development of various conditions & diseases including cancer and premature ageing.
There are two ways to mitigate oxidative stress:
Better lifestyle choices – Regular & adequate sleep, regular exercise, stress-free environment, a health & balanced diet, protection from UV, less exposure to pollutants, etc.
Adequate intake of antioxidants, one of which is Vitamin C.
The skin broadly is made of two layers, the dermis and the epidermis. I discussed the epidermis a little in my post on exfoliation.
The epidermis is the outer layer, its main function is to provide a barrier from environmental factors, pollutants and pathogens, to protect the body structures beneath.
Beneath the epidermis, lies the dermis. The dermis is connected to blood vessels. The dermis supports connective tissues, specifically collagen and elastin, sweat glands, sebaceous glands, hair follicle, lymph vessels and nerve endings. Fat and muscle lie below the dermis. Dermis plays various roles & functions. With age, collagen and elastin fibres start to break and the layers of the skin start to thin out. This cause wrinkles to form.
This graphical representation can help you understand the above information better.
Nutrition has been known to play a role in skin health. There are various manifestations of scurvy, some of which are skin ailments. This article supports the role of micro & macronutrients in the skin.
Here I have quoted findings of this study
Subjects: Twenty-seven healthy female volunteers were recruited from community bulletin board of Kyung Hee University from March to April, 2014. Inclusion criteria were non-smoker, no vitamin and mineral supplements, non-pregnancy, non-alcoholism, no known medical illness, and women aged 20–49 years.
Experiment: Total of 27 subjects were divided into 3 groups of which were the placebo group (n = 9), supplementation group of 100 mg/day vitamin C (n = 9), and supplementation group of 2,000 mg/day vitamin C (n = 9) and 24 subjects completed all the necessary requirements.
Result: The study showed plasma vitamin C levels were increased after 100 mg and 2,000 mg of vitamin C supplementation, and plasma vitamin C levels were not significantly different between groups after supplementation. These findings are consistent with other interventions in which supplementation of 30 to 2,500 mg increased plasma vitamin C concentration. Though vitamin C supplementation increased plasma vitamin C concentration, intake only within 30 and 100 mg/day may affected vitamin C availability to tissue. Doses above 500 mg/day resulted in little further increase in plasma vitamin C concentration and absorbed doses were almost entirely excreted in the urine.
Here is another study:
Subjects: Seven men ages 20-26 years were selected. Exclusion criteria were cigarette smoking, use of regular medications, history of kidney stones, glucose-6-phosphate dehydrogenase deficiency, diabetes mellitus, bleeding disorders, or family history of iron overload/hemochromatosis. Patients consumed a vitamin C-restricted diet throughout hospitalization, which contained <5 mg of vitamin C daily and utilized a computerized 14-day-cycle selective menu design. On admission patients began vitamin C depletion to reduce plasma vitamin C concentrations to 5-10 um without scurvy. Plasma vitamin C was measured every 1-4 days.
Experiment: For repletion, daily ascorbate doses were 30, 60, 100, 200, 400, 1000, and 2500 mg given sequentially (see below). Half of the dose was ingested twice daily to simulate vitamin C consumption in foods. Doses were given in the fasting state ( 1.5 h before meals or -2 h after meals and morning vitamin C prior to breakfast). Bioavailability was studied for the ingested dose (single doses of 15, 30, 50, 100, 200, 500 and 1250 mg).
Result: This table summarises some findings. The plasma concentration of Vitamin C increased in all subjects with depleted vitamin C concentrations. Neutrophils, monocytes, and lymphocytes saturated at 100 mg daily and contained concentrations at least 14-fold higher than plasma. Bioavailability was complete for 200 mg of vitamin C as a single dose. No vitamin C was excreted in urine of six of seven volunteers until the 100-mg dose. At single doses of 500 mg and higher, bioavailability declined and the absorbed amount was excreted. Complete plasma saturation occurred at 1000 mg at the expense of decreased bioavailability and increased urinary excretion. Based on these data and the Institute of Medicine criteria, the current RDA of 60 mg daily should be increased to 200 mg daily, which can be obtained from fruits and vegetables. Safe doses of vitamin C are less than 1000 mg daily, and vitamin C daily doses above 400 mg have no evident value.
In conclusion: Supplementation of Vitamin C has been known to increase Vitamin C levels in the blood Plasma but not Vitamin C Concentration in humans that did not have a deficiency. While vitamin C concentration depends also depends on absorption and transmission mechanisms, supplementation of up to 200mg in a single dose can help individuals who have a deficiency of Vitamin C.
This simply means if you do not have a deficiency, gulping Celin 500mg will make your urine rich loaded with Vitamin C. Also means, small single dosage of 100-200mg from fruits and vegetables would be better than a single large dosage if you wish to elevate your vitamin c levels.
There is one study however that shows that combined oral intake of Vitamin E with Vitamin C helped to be effective against sunburns.
Recommended Dietary Allowances (RDAs) for Vitamin C based on this study report.
Vitamin C content of some common fruits and veggies :
Coming back to the skin –
To my surprise, Vitamin C concentration in the skin is higher than the tissues of various other organs. Reference Table
Vitamin C is generally stored in the intracellular fluid (inside the cell) where it brought by the blood vessels. Since the blood vessels are well connected to the dermis, Vitamin c is transported to the dermis by the blood vessels. It is important to note that dermis is where collagen and elastin fibres are present. Also, surprisingly the Vitamin C concentrations are found to be much higher in the epidermis (not connected to the blood vessels but where UV damage first occurs). Thus, researchers believe that the skin stores more Vitamin C to protect itself from the rapid oxidative damage because of UV and other environmental factors in healthy individuals.
SO WHAT DID I LEARN FROM ALL OF THE ABOVE??
Vitamin C essential for good health AND GOOD SKIN.
Our body cannot produce its own Vitamin C.
Meeting daily RDA is sufficient to keep high concentrations of Vitamin C in the skin, for most individuals.
Veggies like bell peppers & broccoli and, fruits like papaya have more vitamin C than a lemon/amla.
Supplementation of Vitamin C is only beneficial if you have a preexisting deficiency.
Supplementation over 1g in a single dosage will only increase plasma levels but be excited in almost all the excess will be excreted in the urine.
It’s better to get your daily dose from fruits and veggies.
Oxidative stress can be reduced by having a good lifestyle. Daily exercise, sound sleep, less stress, sun protection and a balanced diet actually play a MAJOR role in reducing oxidative damage. Thus, the best way to anti-age is to invest in self-care through mindfulness. (This is something we all know, but we do not consider it important enough. I need to work on myself. It’s been mindblowing to read all the studies that point out these facts.)
I am breaking this journey in 2-3 parts. There is a lot of information. The next post will cover topical benefits and derivates.
Link to Part 2: All About TOPICAL VITAMIN C —- L-AA & Derivatives