, Dagmar Curjel Wilson conducted a survey among several thousands of school age children in what was then northern India. He concluded that the causes of rickets were predominantly social, such as purdah, (wearing of the the veil and burka, and seclusion for females), as well as poor housing design preventing access to sunlight, and an inadequate diet.
Since then, evidence of burkas causing a chemical deficiency of vitamin D has come to light from various sources. A 2001
study by Sonia R Grover and Ruth Morley was carried out among pregnant women at an antenatal clinic in the Royal Women's Hospital, a teaching hospital in Melbourne, Victoria. The study concerned 94 women who were veiled or of dark skin. 82 of these agreed to be screened, and 66 women (80%) were found to be having low levels of Serum 25-hydroxyvitamin D3.
Another study from Australia published in the same year, carried out by Josephine M. Nozza and Christine P. Rodda
discovered that of 55 children who were found to have osteomalacia, 54 of these were from mothers who had the ethnocultural factors (wearing veils/burkas and/or dark skin) expected. When 31 of the 55 mothers were tested (81%), 25 of these (81%) were found to have low levels of 25-hydroxyvitamin D3, consistent with osteomalacia. The evidence had been gathered in two clinical admisitrative regions in Melbourne Victoria between June 1994 and February 1999.
More reports on Australia and Vitamin D deficiency among "multiethnic" Australians can be found here
and in another report
concerning Sydney. The latter report found that an increasing number of cases of children with rickets was being discovered in Sydney. 126 cases were diagnosed between 1993 and 2003. Almost exclusively, the incidence of childhood rickets came either from Africa (33%), the Indian subcontinent (37%) and the Middle East (11%). 79% of the cases were children born in Australia. A third of the cases presented initially with the hypocalcaemic seizures, and 22% already had bowed legs.
A study of Arab women in Denmark (Calcif Tissue Int 2000; 66: 419-424) by researchers Glerup, Mikkelsen, Poulsen and others found that a group of Arab women suffering from muscle pain and weakness were suffering from a deficiency of vitamin D, which improved after three months of vitamin D therapy.
Another Australian study reported in the Proceedings of the 9th Annual Scientific Meeting of the Australia and New Zealand Bone and Mineral Society, Cairns, June 1999, found that Muslim women were 2.5 times more likely to be suffering from bone pains and osteoporosis than women of European descent.
So what is happening, it appears, is that traditional methods of covering up women in burkas depletes the available vitamin D in the body, leading to symptoms related to or directly causing rickets. But additionally, it also appears that these women then give birth to children who also have a lack of the necessary vitamin D byproducts to prevent rickets, unless these children are exposed while very young to sunlight, the source of most of the body's natural vitamin D.
In women who only breast fed their infants from the affected groups in the Australian studies, there appeared to be a higher incidence of children who had rickets and its related symptoms. Milk formulas and most cows' milk in the West has additional vitamin D added. But normal breast milk contains only minimal amounts
of vitamin D, probably due to our evolutionary origins in tropical and sunny climes.