Pale-skinned people at risk for vitamin D deficiency
MedWire News: People with pale skin are often deficient in vitamin D and may benefit from taking supplements, say UK researchers.
They believe that fair-skinned people - those with freckles, blue eyes, or a tendency to sunburn - may be unable to maintain adequate levels of vitamin D in their bodies.
This could be because pale-skinned individuals try to avoid being in the sun for fear of sunburn and/or because of genetic factors governing the amount of vitamin D made in their bodies.
The study was undertaken by Dr John Davies and colleagues from the Cancer Research UK Centre at the University of Leeds, UK, and is published in the journal Cancer Causes and Control.
They wanted to investigate the various factors that influence levels of vitamin D in the blood. Vitamin D is made in the body, upon exposure to sunlight, and can also be found in foods such as fortified milk, butter, eggs, and fatty fish.
Professor Newton-Bishop's team analyzed information on around 1200 people who had participated in an unrelated study. Some of the people were healthy and some had been diagnosed with a form of skin cancer known as melanoma.
To the team's surprise, over half of participants had "suboptimal" levels of vitamin D, defined as levels below 60 nmol/l. This cutoff was chosen because there is evidence that levels below 60 nmol/l are associated with an increased risk of heart disease and poorer survival from skin cancer.
Interestingly, suboptimal levels of vitamin D were widespread in both healthy individuals and those with skin cancer (who are known to be susceptible to low vitamin D levels).
More detailed investigation showed that people with low vitamin D levels tended to be those with a particular genetic variant and those with pale skin.
"Fair-skinned individuals who burn in the sun tended to have lower levels of vitamin D," said Professor Newton-Bishop. "Our data suggested that this was because they spent less time in the sun but probably was also related to covering up more."
Based on their findings, the researchers recommend that everyone should be aware of national guidelines on vitamin D intake - currently set at 600 IU for those aged up to 70 years and 800 IU for the over-70s.
However, people with pale skin and those who avoid the sun should consider talking to their physician about whether they might be deficient in vitamin D - and whether they may benefit from taking vitamin D supplements.
"If you are worried about your vitamin D levels, our advice is to go see your doctor," remarked Sara Hiom, health information specialist from Cancer Research UK.
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By Joanna Lyford