Vitamin C is well known by this point in time as an antioxidant. It has been incorporated into daily multivitamins, single vitamin supplements, cold/flu prevention supplements, and topical skincare. For this research, I’m not focusing on the health effects of vitamin C. Many others on the internet and YouTube are doing so; I do not need to be redundant. Similarly, I’m not going to address topical delivery, because that’s not what the supplements do. So, what is the evidence that taking supplements of vitamin C can help your skin? Is there any good data on that?
Honestly, this has an obvious answer of yes. We discovered long ago that vitamin C is critical for the formation of collagen, which is found in skin, bones, and many other tissues in the body. In fact, it is the single most common protein in the human (or mammalian) body . Vitamin C deficiency causes scurvy—and that’s just plain unattractive.
I searched for the phrase oral supplementation vitamin c skin and found 138 results from JID, 37 from PubMed, and 117,000 from Google Scholar. This was a very surprisingly small number of results. I actually looked at all the titles for the JID and PubMed searches, but I only went through the first three pages of Google Scholar results. I very quickly understood that very little active research has been done on taking oral supplements of vitamin C and their impact on skin health. If you need you, you can find out more about how I do the literature search and review.
The best study I saw looked at antioxidant capacity of skin after vitamin C supplementation : that is, how well can the skin break down free radicals. In this study, participants aged 22-57 took either a 100 mg dose or a 180 mg dose of vitamin C daily. Compared to baseline, both doses of vitamin C improved the antioxidant capacity significantly, but there wasn’t any real difference between the two doses. These effects became apparent in as little as two weeks. The placebo group showed no change. The only limiting factor on this study is that it was a small number of people (n=33). What impressed me most about this study was the study design: the study participants were about half and half on gender, and this study did not rely on expert grading by people. It used a non-invasive technique where (short version) the skin was treated with a free radical and then evaluated by spectroscopy.
Honestly, this made me question how long it takes for the vitamin C levels in the body to reach peak levels (pharmacokinetics) and I wanted more information than just the government recommendations. I only looked at one study. This one showed that you reach peak levels of vitamin C in the blood and skin after 20-80 days depending on dose . The higher doses of 100 and 200 mg daily took longer, but gave more stable blood levels over time; the current recommended daily value of 60 mg. They tested higher doses, too, but found that above 200 mg didn’t offer any benefit. That was actually consistent with another study looking at oral vitamin C and UV stress on skin. This study was very small (n=12 participants), but they measured blood and skin levels of vitamin C using a 500 mg dose. Both levels increased but then tapered off and stabilized. However, they found no significant difference in skin reddening with UV exposure in the vitamin C group, but there was some reduction in lipid damage . I guess that makes sense; vitamin C doesn’t prevent you from getting a sunburn, but it is supposed to help reduce the effects.
The remaining articles that were pertinent used an antioxidant mixture where vitamin C was one of the components. This is not ideal, because we cannot determine what effects are due to which components. However, this is also true of the Halo Beauty supplement, and they help to demonstrate that taking oral antioxidants helps improve skin, so I think they’re still relevant. The first one that was particularly well done tested n=35 women aged 40-75 over an 8-week period. Before and after photos were taken in a climate-controlled room with the same temperature and humidity, and subjects had to sit in the room 15 minutes prior to photos. They were not allowed to use skincare products beginning the night before photos were taken. These photos were then rated by expert graders for coloring, luminosity, brightness, and transparency, all of which were considered significantly improved . Another study looking at a different combination antioxidant treatment prohibited study participants from using anything except facial soap for the 90 days of the study (can you imagine?). However, again, it was a blend-and in this particular study, it wasn’t even the was being used as a control for the main focus (fermented papaya, yum). This study also used before-and-after photos with expert skin graders, but they were blinded to which participants received which treatment. The antioxidant blend group saw a reduction in lipid damage (consistent with the study ), but not in terms of skin elasticity or even-ness . They also didn’t see any major changes in gene expression relating to inflammation. However, they did see an increase in moisturization from about 38% to about 50%, which may be more interesting given that no moisturizers were permitted !
This next study was done in mice and looked at skin wrinkling and thickness. Again, it used an antioxidant blend containing vitamin C. Mice are not humans… but the study did show that their oral blend reduced both wrinkles and skin thickening caused by UV damage , so maybe there’s hope!
Lest you think that I focused only on the positive studies, there was one in 2007 that looked at the long-term risk of skin cancer in 7,876 men and women who took either an antioxidant blend containing vitamin C or a placebo . They found an increased risk of skin cancer in women who took the antioxidants, but not in the men, and not in the placebo group. The incidence of melanoma was also slightly higher. This doesn’t tell us why this happened-it may have had something to do with the supplement, or maybe there were other risk factors.
So there’s my update on vitamin C and what we know about what oral supplementation does (and doesn’t do) for skin. Alone or in combination with other antioxidants, there seems to be some evidence that it’s beneficial for normal, healthy people. The levels of vitamin C found in Halo Beauty (60 mg) are at the recommended daily intake, but you also get some from food sources (and other vitamins you may take). This research also tells us that more is okay up to a point, but there’s no benefit to anything above 200 mg or so; that’s well below the toxicity dose, so this is pretty safe.
Next up: Vitamin D3!
- Collagen, in Wikipedia. 2018.
- Lauer, A.-C., et al., Dose-Dependent Vitamin C Uptake and Radical Scavenging Activity in Human Skin Measured with in vivo Electron Paramagnetic Resonance Spectroscopy. Skin Pharmacology and Physiology, 2013. 26(3): p. 147-154.
- Levine, M., et al., Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. Proceedings of the National Academy of Sciences of the United States of America, 1996. 93(8): p. 3704-3709.
- McArdle, F., et al., UVR-induced oxidative stress in human skin in vivo: effects of oral vitamin C supplementation. Free Radical Biology and Medicine, 2002. 33(10): p. 1355-1362.
- Dumoulin, M., D. Gaudout, and B. Lemaire, Clinical effects of an oral supplement rich in antioxidants on skin radiance in women. Clinical, Cosmetic, and Investigational Dermatology, 2016: p. 315-324.
- Bertuccelli, G., et al., Effect of a quality-controlled fermented nutraceutical on skin aging markers: An antioxidant-control, double-blind study. Exp Ther Med, 2016. 11(3): p. 909-916.
- Ho-Song, C., et al., Anti-wrinkling effects of the mixture of vitamin C, vitamin E, pycnogenol and evening primrose oil, and molecular mechanisms on hairless mouse skin caused by chronic ultraviolet B irradiation. Photodermatology, Photoimmunology & Photomedicine, 2007. 23(5): p. 155-162.
- Hercberg, S., et al., Antioxidant supplementation increases the risk of skin cancers in women but not in men. J Nutr, 2007. 137(9): p. 2098-105.