Out into the light!

How much sun is enough for your child?

By Prof Alfred Längler 

People, like plants, need sunlight for healthy growth. For infants and small children in particular, it’s important for the development of their bone structure. But getting too much sun is also inadvisable. Why do we need vitamin D, and how is it produced? How often and for how long should children stay in the sun?

Paediatrician Prof. Dr. Alfred Längler offers answers and advice.

Only sunlight, or more precisely the UV radiation contained in sunlight, makes it possible for children to develop a healthy skeleton. We need healthy bones in order to stand and walk upright. At birth, most of a child’s bones that will later become hard are actually made of cartilage. Proper bone mineralisation only occurs when children take in minerals and nutrients such as calcium and phosphorus with their food. These two important substances are then incorporated into the cartilaginous bones, thanks to vitamin D.

Most foods only contain a small amount of vitamin D; higher amounts are present in fish liver oil and oily fish. We can also produce a large amount of the vitamin D that we need by ourselves. This is done with the aid of UV radiation, which we receive when enough sunlight shines on our skin.

If vitamin D is lacking, our bones cannot develop properly. In infants, for example, a severe vitamin D deficiency can lead to rickets. This is why vitamin D supplements are recommended for infants in Germany, for example. Breast milk is the best nutrition for babies. But it contains only a relatively small amount of vitamin D. Industrially produced infant formulas must be enriched with vitamin D (up to 15 μg or 600 IU/litre).

To ensure that they produce sufficient vitamin D in their skin, babies and small children should be exposed to sunlight for 30 to 60 minutes a day. It’s enough if their face is exposed to the blue sky. Direct sunshine is not necessary.

But too much sunlight can have negative consequences, especially for infants and small children. At this age, a child’s skin is still quite thin and has few melanocytes (skin cells that produce the protective skin-tanning pigment melanin). This means that even a relatively short period of exposure to the sun can cause sunburn. Like any other burn, this manifests itself through a reddening of the skin, and in extreme cases causes blistering. Sunburn in childhood can significantly increase the risk for the later development of skin cancer. This is partly due to the fact that a child’s immune system is not yet fully developed and so it is unable to repair the cell damage caused by the sun’s rays.

By following a few important guidelines, parents can let their children enjoy the benefits of sunlight without exposing them to the unnecessary and avoidable risks of sun exposure.

• The younger the child, the more important it is that he/she does not stay in the blazing sun (especially not around midday).
• Your child’s skin should always be sufficiently covered, with a sun hat (with neck protection) and light cotton clothing.
• Use a sunscreen with SPF 20 and higher, without synthetic perfumes and preservatives.
• Sunscreen should be applied with particular care to the outer ears, nose and tops of the feet.  

Even if children wear sunscreen, this doesn’t mean that they should remain in the direct sun for longer periods of time. If sunburn does occur despite taking the above precautions, immediate and effective treatment is required.

Prof Alfred Längler is Senior Physician in the Department of Paediatrics and Adolescent Medicine at the Community Hospital in Herdecke and Professor of Integrative Paediatrics and Adolescent Medicine at the University of Witten/Herdecke.