Exposure to sunlight is most people’s principal source of vitamin D. Vitamin D is vital throughout life to maintain good bone health and inadequate vitamin D can cause rickets in children and bone disease in adults. UK levels of vitamin D deficiency are high (particularly among people with darker skin and during the winter months) and there is evidence that this is a growing problem.

Professor Ann Webb, Professor of Atmospheric Radiation, commented: “Vitamin D is really important for healthy bones. When it comes to safe sunlight exposure and vitamin D, our research shows that ‘little and often’ is the best approach for most people.”

Professor Lesley Rhodes, Clinical Professor of Experimental Dermatology, added: “Many people in the UK get insufficient vitamin D. Our research shows that regular, low levels of sunlight exposure can help alleviate the problems of vitamin D deficiency in the UK.”

Researchers at the University of Manchester have been looking into the relationships between sunlight exposure and vitamin D. In simple terms, they have found that – for lighter skin types – daily sunlight exposure for 10-15 minutes between April and September provides sufficient year-round vitamin D while also minimising the risks of sunburn and skin cancer. For darker skin types, 25-40 minutes is recommended.

Importantly, levels of sunlight exposure that make an individual’s skin look pink or sunburnt – either during or some hours after exposure – are too high and should always be avoided. People with very light or sensitive skin and others who may not be able to follow this advice should seek further guidance from their doctor about alternative sources of vitamin D. The full advice is on the project website.

Further reading:

How to stay safe in the sun    Are you at risk of skin cancer?