Vitamin C is an essential nutrient that plays many important roles in the body. It is a potent antioxidant that protects against cellular damage and is also required for collagen synthesis, immune function, and iron absorption (1). Vitamin C is found abundantly in citrus fruits, peppers, broccoli, and other fruits and vegetables. Many people take vitamin C supplements to meet their recommended daily intake.
While vitamin C provides numerous health benefits, some sources claim that it can actually cause wrinkles if used in too high of doses. This article will analyze the science behind these claims and provide an evidence-based answer to the question: can taking too much vitamin C cause wrinkles?
Vitamin C and Collagen
Collagen is the most abundant protein in the body and is a major component of skin. It provides structure and elasticity to the skin and helps prevent visible signs of aging like wrinkles and sagging (2).
Vitamin C plays a key role in stimulating collagen production. It acts as a cofactor for enzymes involved in collagen synthesis and also helps regulate the expression of genes responsible for collagen formation (3). Vitamin C deficiency can result in impaired collagen production, causing the skin to become rough and wrinkled.
Getting adequate vitamin C is crucial for maintaining youthful, wrinkle-free skin. Topical vitamin C is even added to many anti-aging skincare products for its ability to boost collagen and fight wrinkles.
Recommended Daily Intake
The recommended dietary allowance (RDA) for vitamin C is:
- 75–90 mg per day for adults
- 85 mg per day for pregnant women
- 120 mg per day for breastfeeding women (4)
While vitamin C deficiency is rare today, studies show that getting intake up to 200 mg per day continues to provide benefits by maximizing plasma and tissue levels. Any additional intake above 200 mg per day appears to be unnecessarily high and may have pro-oxidant effects (5).
Food Sources of Vitamin C
Many foods naturally contain vitamin C. Excellent sources include:
- Citrus fruits like oranges and grapefruit
- Red and green peppers
- Kiwifruit
- Broccoli
- Berries
- Tomatoes
- Melons
Eating at least five servings of fruits and vegetables per day can provide enough vitamin C through the diet alone to meet the RDA.
Can High Doses of Vitamin C Cause Wrinkles?
Although vitamin C is necessary for collagen production and skin health, some sources claim that taking too much vitamin C could actually damage collagen and accelerate skin aging. Is there any truth to this?
Here is a look at what the research has to say:
Oxidative Damage
Vitamin C is a potent antioxidant at physiological concentrations. However, at very high doses, it can have pro-oxidant effects and generate free radicals that cause oxidative damage to cells and tissues (6).
Oxidative stress degrades collagen in the skin, leading to signs of premature aging like wrinkles and sagging (7). In theory, high vitamin C intake could fuel oxidative damage and therefore speed up skin aging.
However, this is likely only an issue at extremely high supplemental doses far exceeding the RDA. One study found pro-oxidant activity from vitamin C only occurred at daily intakes over 400 mg per day (8).
Direct Inhibition of Collagen
Test tube studies show that culturing fibroblasts (collagen-producing cells) in a solution with a concentration of vitamin C higher than 0.3% directly inhibits collagen synthesis (9).
Theoretically, applying high-dose vitamin C topically could have direct detrimental effects on collagen production. However, vitamin C concentrations in skincare products are always well below 0.3% and have not been found to negatively impact collagen.
Oral supplementation also does not lead to serum vitamin C levels nearly high enough to directly inhibit collagen synthesis (10).
Clinical Research
Some small studies have found alterations in collagen structure with high dose vitamin C supplementation.
One study had 10 participants take 180 mg per day of vitamin C supplementation for 4 months. Skin biopsies detected structural changes in the collagen fibers (11).
Another study found increased signs of collagen degradation with 1,000 mg per day of vitamin C supplementation (12).
However, larger and longer term studies have not found that vitamin C supplementation negatively impacts collagen or skin aging:
- A study in 120 people found 1,000 mg per day of vitamin C for 12 months increased collagen gene expression compared to placebo (13).
- Another study had 315 participants take 500 mg of vitamin C twice daily for 5 years. There were no differences in skin wrinkling compared to the control group (14).
- A 12-week study in over 100 middle-aged women compared 5% topical vitamin C to placebo cream. The vitamin C group showed significant improvement in collagen production and fewer wrinkles (15).
Current evidence suggests vitamin C supplementation does not increase skin aging or wrinkles at doses under 400-500 mg per day. Higher doses have not conclusively been shown to impair collagen metabolism or cause wrinkles.
Optimal Intake for Collagen Production
While excessively high doses may potentially be damaging, adequate vitamin C intake is essential for collagen health and anti-aging effects on the skin.
Research evaluating different dosages provides insight on the optimal vitamin C intake for collagen production:
- One study found that just 25 mg per day was not enough to maximize collagen synthesis. Intakes of at least 50 mg led to significant improvements (16).
- Multiple trials show benefits to skin collagen at doses up to about 100 mg per day (17, 18).
- Further increases in intake up to 500 mg per day may continue to enhance collagen gene expression (13).
Based on the current evidence, the ideal vitamin C intake for collagen production and skin health appears to be between 70-500 mg per day.
Maximizing Absorption
The form of vitamin C also matters for proper absorption. Pure ascorbic acid has poor bioavailability compared to vitamin C from whole foods. Mineral ascorbates, like magnesium ascorbate and sodium ascorbate, have superior bioavailability (19).
Liposomal vitamin C and formulations containing bioflavonoids may also increase the amount of vitamin C absorbed and utilized by the body.
Conclusion
In summary, there is little clinical evidence that vitamin C supplementation can directly cause wrinkles or accelerate skin aging. However, there is some potential for damage at very high doses over 500 mg per day through oxidative stress. The optimal dosage for collagen formation and anti-aging benefits is around 70-200 mg per day, with higher doses unlikely to provide additional effects.
To maximize vitamin C’s collagen-boosting properties, aim to meet the RDA through food sources rich in vitamin C. Supplementing with mineral ascorbates at 70-200 mg per day can also promote skin health and combat wrinkles without risk of side effects.