Dr's Casebook column with Dr KeithSouter: Boosting your daily intake of vitamin C rich food can improve your skin

But recent research from New Zealand and Germany has shown that boosting vitamin C in the diet has a direct effect on the skin to strengthen collagen and accelerate skin growth. Quite simply, vitamin C rich foods get to parts of the skin that creams can’t reach.

Collagen provides structure, elasticity, and hydration to the skin, but its production declines by about one per cent every year from about the age of 25.

This recent research published in the Journal of Investigative Dermatology, found that vitamin C levels in the skin closely mirror levels in the blood. They found that increasing intake through vitamin C rich foods was shown to raise both blood and skin concentrations.

In their study they recruited 24 healthy adults in New Zealand and Germany. They asked the participants to eat two vitamin C rich kiwifruit each day, and in doing so they found that they showed a definite increase in vitamin C within their skin. Significantly, they found that this increase was directly associated with an increased production of collagen and measurably thicker skin and greater renewal of the outer skin layer.They were particularly surprised that vitamin C in the blood reached every layer of the skin and improved skin function.

Skin care creams have vitamin C added, but it does not penetrate the outer skin layer well. On the other hand dietary vitamin C boosts the blood level and the deeper skin cells absorb the vitamin C from the blood. This is why dietary vitamin C is more effective.

In the study the participants were asked to eat two kiwifruit daily for eight weeks. This provided the equivalent of 250 micrograms of vitamin C. They collected skin samples before and after the study so that the skin layers could be studied in different research centres using different techniques. These included using ultrasound to measure skin thickness, elasticity, UV protection and rates of epidermal cell renewal. Effectively, they could assess and compare the function of the skin pre and post study. They found a measurable increase in skin thickness among participants, indicating increased collagen production as well as faster renewal of the epidermal cells.

Kiwifruit was selected for the study because of its consistently high vitamin C content, but they suggest that similar benefits can be gained from other vitamin C rich foods, especially fresh fruits and vegetables such as citrus, berries, peppers and broccoli.

Vitamin C cannot be stored by the body or the skin so to get the maximal benefit the level has to be maintained, by taking vitamin C intake of around 250mg per day. If you make sure you take your five fruit and veg a day, every, just ensure that one is a high vitamin C