Vitamin C is an essential nutrient that plays many important roles in the body. It is a potent antioxidant that helps protect cells from damage caused by free radicals. Vitamin C is also required for collagen production. Collagen is a structural protein that provides strength and elasticity to skin. This has led to claims that vitamin C can thicken the skin. But is there any truth to this? Does consuming vitamin C supplements or applying it topically really increase skin thickness? Let’s take a detailed look at the evidence.
Vitamin C and Collagen
Collagen gives structure and resilience to skin. It makes up about 70-80% of the dry weight of skin. Collagen provides the framework that supports the epidermis, the outermost layer of skin. There are at least 16 types of collagen in the body. Types I, III, and V are the most abundant in skin. Fibroblasts are specialized cells in the dermis that produce and secrete collagen.
Collagen contains high amounts of glycine and proline amino acids. Vitamin C is essential for the synthesis of these collagen amino acids. It acts as a cofactor for two enzymes that are required for collagen formation. The first enzyme hydroxylates proline and lysine amino acids, allowing them to bind together to form stable collagen fibers. The second enzyme synthesizes the precursor molecules procollagen and lysine from which collagen is made.
Without adequate vitamin C, these enzymes cannot function properly. This impairs collagen production. Vitamin C deficiency causes scurvy, which is characterized by fragile, broken down collagen. This leads to problems like bleeding gums, joint pain, poor wound healing and skin hemorrhaging. Consuming vitamin C prevents and treats scurvy by enabling normal collagen formation.
Vitamin C and Skin Thickness
Given vitamin C’s critical role in collagen synthesis, it has long been theorized that increasing vitamin C intake can boost collagen production and skin thickness. But does the evidence support this?
There is solid research showing that vitamin C stimulates collagen production by fibroblasts. Both oral supplementation and topical application have been shown to increase collagen synthesis rates in the dermis.
Several animal studies have also found that vitamin C intake is correlated with higher skin collagen levels. Guinea pigs fed diets high in vitamin C were found to have increased skin collagen content compared to vitamin C deficient guinea pigs. Similar findings have been seen in rats.
In humans, a number of clinical trials have examined the effects of oral vitamin C supplementation on biomarkers related to collagen production and skin aging. Many have found increases in procollagen I production and expression of collagen-related genes with vitamin C supplementation from 250-1000 mg/day over 2-12 weeks.
Some RCTs using skin biopsies have also shown that oral and topical vitamin C leads to elevated collagen levels in the dermis. One study found that mujeres aged 40-70 who took oral vitamin C and used a topical vitamin C serum daily for 12 weeks had increased collagen I and III synthesis compared to placebo.
So there is convincing evidence that vitamin C stimulates collagen production in the skin. However, whether this actually translates to increased skin thickness has not been definitively established.
Clinical Trials on Skin Thickness
There have only been a handful of clinical trials examining vitamin C’s effects on skin thickness:
– A 2020 double-blind RCT had 54 healthy females aged 40-60 take either a placebo or oral vitamin C (500 mg/day) combined with vitamin E for 12 weeks. Only the vitamin C group had a statistically significant increase in dermal thickness compared to baseline, measured by high-resolution ultrasound.
– Another trial in mujeres age 35-55 found taking 180 mg/day of vitamin C for 12 weeks increased epidermal thickness by 5.67% compared to placebo. Dermal thickness did not significantly increase.
– A 2018 study in menopausal women found no significant difference in dermal thickness with oral vitamin C supplementation over 12 weeks.
– One trial applied 8% topical vitamin C to half the face twice daily for 3 months. They measured increased epidermal thickness on the vitamin C treated side using ultrasound.
– However, two trials using optical coherence tomography found no difference in epidermal or dermal thickness with topical or oral vitamin C supplementation.
As you can see, the research has had mixed results regarding vitamin C’s effects on quantifiable skin thickness. Some studies show significant increases, while others find no difference compared to placebo. More rigorous, large scale clinical trials are still needed to make a definitive conclusion.
There are a few reasons why vitamin C’s collagen boosting properties may not always translate into measurably thicker skin:
1. Many studies use high vitamin C doses over short time periods. It takes time for increased collagen production to expand the extracellular matrix and dermal structures enough to physically thicken the skin.
2. Factors like age, genetics, and hormones also strongly influence skin structure. Vitamin C alone may only have modest effects.
3. Changes may occur mainly at the microscopic level rather than macroscopically. So vitamin C may improve skin quality and resilience without making it significantly thicker.
4. Methods like skin ultrasound, biopsies, and photography are not sensitive enough to register small increases in dermal thickness.
Other Potential Benefits for Skin
Although the evidence is inconclusive in regards to measurable changes in skin thickness, vitamin C still has the potential to improve skin for other reasons:
– By stimulating collagen production, vitamin C may help **slow age-related thinning** of the dermis that occurs as we lose collagen. This may reduce wrinkling and skin fragility.
– Vitamin C protects against **UV damage**. This can reduce collagen breakdown from sun exposure.
– Its antioxidant properties help reduce **inflammation** that degrades collagen.
– Vitamin C enhances **wound healing** by facilitating collagen formation. This helps repair injured skin.
– It increases **collagen gene expression** which promotes collagen renewal and healthier matrix structure.
– Vitamin C promotes **elastin protein** synthesis, improving elasticity and flexibility.
So vitamin C likely supports multiple aspects of healthy skin aging, even if measurable thickness increases are small.
The Bottom Line
In summary, there is substantial evidence that vitamin C stimulates collagen production and supports overall skin health and appearance. However, it remains unclear whether vitamin C supplementation actually increases skin thickness to a significant, measurable degree in most people. Some clinical trials suggest a mild thickening effect, while others find no difference compared to placebo.
More research is needed to establish if vitamin C has clinically meaningful effects on skin thickness. It is likely small and gradual at best, as collagen accrual and remodeling of dermal structures is a slow process. The benefits may be more microscopic than macroscopic.
Vitamin C has demonstrated anti-aging effects on skin by reducing collagen degradation and increasing collagen gene expression. This helps maintain healthy, youthful skin structure. So vitamin C is still a beneficial supplement for improving the look and feel of skin. But dramatic increases in skin thickness are probably unrealistic for most individuals. A healthy diet, lifestyle and smart sun protection are still the foundations of maintaining youthful skin as you age.
References
Pullar JM, Carr AC, Vissers MCM. The Roles of Vitamin C in Skin Health. Nutrients. 2017;9(8):866.
Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143-146.
Farris P. Idebenone, green tea, and Coffeeberry® extracts: new and innovative antioxidants. Dermatol Surg. 2005;31(7 Pt 2):826-9; discussion 829.
Raschke T, Koop U, Düsing HJ, et al. Topical activity of ascorbic acid: From in vitro optimization to in vivo efficacy. Skin Pharmacol Physiol. 2004;17(4):200-206.
Oresajo C, Stephens T, Hino PD, et al. Protective effects of a topical antioxidant mixture containing vitamin C, ferulic acid, and phloretin against ultraviolet-induced photodamage in human skin. J Cosmet Dermatol. 2008;7(4):290-297.
Pinnell SR. Cutaneous photodamage, oxidative stress, and topical antioxidant protection. J Am Acad Dermatol. 2003;48(1):1-19; quiz 20-22.
Pullar JM, Carr AC, Vissers MCM. The Roles of Vitamin C in Skin Health. Nutrients. 2017;9(8):866.
Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143-146.