Fair-skinned people who burn quickly in the sun may need to take supplements to ensure they get the right amount of vitamin D, new research finds.
Cancer Research UK-funded researchers at the University of Leeds suggest that people with very pale skin may be unable to spend enough time in the sun to make the amount of vitamin D the body needs - while also avoiding sunburn.
The study, published in Cancer Causes and Control, suggested that melanoma patients may need vitamin D supplements as well.
But researchers also noted that sunlight and supplements are not the only factors that can determine the level of vitamin D in a person’s body.
Some inherited differences in the way people’s bodies process vitamin D into the active form also have a strong effect on people’s vitamin D levels.
The study defined the optimal amount of vitamin D required by the body as at least 60nmol/L. However at present there is no universally agreed standard definition of an optimal level of vitamin D.
Professor Julia Newton-Bishop, lead author of the study based in the Cancer Research UK Centre at the University of Leeds, said: “Fair-skinned individuals who burn easily are not able to make enough vitamin D from sunlight and so may need to take vitamin D supplements.
“This should be considered for fair-skinned people living in a mild climate like the UK and melanoma patients in particular.”
Researchers took the vitamin D levels of around 1,200 people and found that around 730 people had a sub-optimal level. Those with fair skin had significantly lower levels.
Researchers chose 60nmol/L as the optimal vitamin D level in part because there is evidence that levels lower than this may be linked to greater risk of heart disease and poorer survival from breast cancer.
A consensus between health charities including Cancer Research UK says that levels below 25nmol/L are vitamin D deficient which means that these levels are associated with poor bone health. But some researchers consider that higher levels, around 60nmol/l, may be desirable for optimal health effects.