Vitamin C – An Essential Skin Nutrient

It has been know for decades that vitamin C (ascorbic acid) is essential to our health. Since its discovery in the 1930s, it has been know that its deficiency in humans leads to break down in skin and connective tissue – a condition known as scurvy, so serious that it could be lethal. Over the following decades, scientific research has shed more light on the many roles Vitamin C has in maintaining our skin’s integrity and function:

1. Vitamin C is necessary for collagen synthesis

Collagen is a generic name for a group of filament-shaped proteins found mostly in animals’ flesh and connective tissue. Its role is to provide a structural framework for the body’s various organs. Most collagen  is synthesised in a specialist cells called fibroblasts.

Collagen synthesis is a complex process by which aminoacids are assembled into peptides, which are then linked in the triple helix structure of collagen. This linking process requires two co-factors: vitamin C and iron. If vitamin C is deficient, the three strands of the collagen molecule are not properly linked together and the molecule is weak and easily destroyed. During collagen synthesis, vitamin C is oxidised and becomes useless, so the supply must be continuously renewed.

The role of Vitamin C in collagen production doesn’t stop here. Research has uncovered several other mechanisms through which vitamin C promotes collagen syntheses:

  • by stimulating the proliferation of fibroblasts, the specialist cells that make collagen. (Research info)
  • by increasing the pro-collagen messenger RNA – this is responsible for passing the instruction to synthesise collagen from the genes on to cellular entities that synthesise this protein. (Research info)
  • by stimulating the repair of fibroblasts’ DNA (Research info)

2. The antioxidant activity of vitamin C protects against UV damage

Vitamin C is the most abundant water-soluble antioxidant in the body, with an important role in UV protection. Human  skin has developed mechanisms for transporting vitamin C right into its topmost layer. As the epidermis contains no blood vessels, transport proteins are in charge of supplying it with vitamin C. It has been observed that the number of transport proteins in the epidermis increases with exposure to UV. This suggests that the skin has developed a mechanism for increasing its supply of vitamin C as a defence against UV damage. (Research info)

Two studies on humans showed that dietary supplementation with vitamins C and E increases  skin’s ability to protect itself from UV damage. (Research 1 & Research 2 info)   Combining the two vitamins has proven effective, while supplementing the intake of either vitamin on its own has not  made a significant difference. This appears to suggest the existence of some mechanism by which the two vitamins act together in defending human skin against UV damage.

How  can you ensure your skin has a good supply of vitamin C?

The most reliable way is dietary intake. These days vitamin C deficiency is an unlikely occurrence in the developed world. But if you want to make sure your body gets all the vitamin C it can use, you can increase the amount of vitamin C rich foods in your diet. Yellow, red and green peppers (in this particular order), strawberries, dark leafy greens, broccoli, cauliflower, kiwi fruit and oranges, are very rich in vitamin C. All fruit and vegetable contain some amount of vitamin C. Increasing the intake of both vitamin C and vitamin E before sun exposure could improve your body’s defences against UV. If you choose to take a vitamin C supplement, the safe upper limit is deemed to be 1,000mg per day.

You are more likely to obtain vitamin C from raw and lightly cooked food, as exposure to heat degrades it. So does exposure to light and air. This is the reason why applying vitamin C directly onto the skin, via creams and lotions is not straightforward. Stabilising Vitamin C in cosmetic products is a challenge for cosmetic manufacturers. The more stable, synthetic derivatives of vitamin C (ascorbate phosphate and ascorbyl palmitate) are less likely to be absorbed into the skin. Once absorbed, they need to be first converted by our cells into vitamin C before they are usable. Therefore obtaining vitamin C from your diet or a food supplement are the most practical ways to ensure you are well supplied with this nutrient.

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