The Health Risks of Wearing Hijabs

This article in July 18, 2007 Daily Mail refers to the hijab, which I believe does leave the face exposed, so I'm not sure if there a British local meaning for the word that leaves even less covered. It is a reminder of the hazards of keeping too much of your skin covered, especially if you are dark skinned in a northern climate:

Muslim women who wear the hijab are at risk of serious illness because they do not get enough sun, doctors have warned.
They said an alarming number of women who cover their skin are suffering bone deficiencies over a lack of vitamin D.
Most of the body's vitamin D - which prevents rickets - is obtained through sunlight acting on the skin. Only a little comes from food.
Doctors told a London conference today that people with dark pigment are at risk because of "cultural reasons" and because they are less efficient at producing the vitamin.
The bone disorder rickets has now broken out in young Muslim children as babies are not getting enough calcium from mothers' breast milk.
The National Health Service is launching a campaign aimed at Muslim women, particularly Bangladeshi, Pakistani and Somalis, to encourage them to increase their vitamin D intake.
A Department of Health spokesman said: "For ethnic groups there is an increased risk of vitamin D deficiency as people with dark and pigmented skin are less efficient at making vitamin D in their skin.
"They need to spend longer outside to make similar amounts and those who wear concealing clothing are unlikely to make enough.
"Studies have shown low vitamin D levels in Asian women in the UK - particularly among those who cover most of their skin for cultural reasons."