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.

Is the 80% absorbed Vitamin C through transdermal route cross the epidermis & dermis layers?