Vitamin C Boosts Epidermal Growth via DNA Demethylation

So possible treatment for age related thinning of the skin.

Well, there are already multiple skin creams with Vitamin C. They have been available for a long time, but they are expensive for what it provides.

Just taking a 500mg x 2 Vitamin C supplements should provide enough for skin repair.

Let's not engage in quakery and resort to knowledge instead.

Oral and transdermal (topical) application of Vitamin C (and other molecules in general) follow completely different routes with different absorption rates and accompanying nuances.

Oral intake. Absorption rate is dosage dependent:

  – At moderate doses (≤ 250 mg/day): 70–90 per cent of ascorbate is absorbed into the bloodstream. Bloodstream means just that – Vitamin C will be distributed throughout the entire body, which includes tissues, internal organs and skin. Active absorption takes place in the small intestine predominantly by SVCT1 and SVCT2 sodium-ascorbate co-transporters.

  – At high doses (≥ 1g a day): passive diffusion takes over and also takes place in the small intestine although now via GLUT transporters that become saturated and absorption efficiency drops to 50 per cent or lower.

The half-life of Vitamin C taken orally is approximately four hours anyway, after which any excess of it still circulating will be rapidly excreted via the renal route (kidneys). Studies report that significantly less than 0.1 per cent makes into the epidermal (skin) layer.

Transdermal (topical) application. Depends on the concentration and several factors, but a 20% concentration serum (not a cream) can achieve a > 80% absorption rate through the skin into receptor fluid after 24 hours. Half-life of Vitamin C applied topically is approximately 4 days.

Recap: less than < 0.1 % / 4 hours half-life for the oral route vs more than 80 % / 4 days half-life for the transdermal route.

Liposomal C will achieve higher concentrations in cells as it doesn't rely on GLUT/SVCT.

Otherwise, the absorption of high doses depends on stress level - when you are not healthy, your body will absorb A LOT more, as shown by vitamin C bowel tolerance method.

To be sure you have it where it counts, take all forms of C - liposomal, film, AA and topical

Ascorbyl palmitate («liposomal C»), when taken orally, is absorbed by the same active‐transport and passive‐diffusion mechanisms as plain vitamin C, with the same saturation thresholds. And it has the same problem as ascorbic acid, sodium ascorbate and calcium ascorbate – it gets distributed throughout the entire body with only minute amounts reaching the «skin».

Topical application of ascorbyl palmitate/«liposomal C», on the other hand, has very poor uptake due to the molecule size being too big to penetrate the skin layer[0]:

  L-ascorbic acid must be formulated at pH levels less than 3.5 to enter the skin. Maximal concentration for optimal percutaneous absorption was 20%. Tissue levels were saturated after three daily applications; the half-life of tissue disappearance was about 4 days. Derivatives of ascorbic acid including magnesium ascorbyl phosphate, ascorbyl-6-palmitate, and dehydroascorbic acid did not increase skin levels of L-ascorbic acid.

Key takeway: «Derivatives of ascorbic acid including magnesium ascorbyl phosphate, ascorbyl-6-palmitate (a.k.a «liposomal C», and dehydroascorbic acid did not increase skin levels of L-ascorbic acid».

[0] Source: https://europepmc.org/article/MED/11207686

Liposomal C IS NOT ascorbyl palmitate. The point is about liposome anyway, not the form of vitamin C. There are a number of research papers showing higher bioavailability, some even claim its similar to IV.

Ah, so you are actually talking about the liposome encased ascorbic acid. I have seen a number of products that misrepresented ascorbyl palmitate as liposomal vitamin C, hence the enquiry.

Taking any form of vitamin C orally still confers statistically insignificant benefits for the skin due to having to propagate and get distributed throughout the entire body.

The article in question discusses the benefits of the topical application of vitamin C, the benefits of which have been extensively studied. Vitamin C (especially in combination with ferulic acid) is amongst very few skincare products that actually work – it has been known for a long time.