Diets and living conditions of Asian boys in Coventry with and without signs of rickets.

1. The diets and living conditions of nin Asian boys with biochemical, and in most instances also radiological, signs of rickets were compared with those of nine other boys who appeared to be normal. The groups were matched according to age, religion, place of father's origin and boy's own place of birth. 2. There were no outstanding differences between the diets of the boys with, and of those without signs of rickets. All had adequate to high calcium intakes. Most of the boys had low intakes of vitamin D, and those withsigns of rickets generally had lower intakes than the normal boys. The food tables used for making the calculations of vitamin D intakes report the amount of the vitamin in the lipid fraction of milk. If it proves to be true that most of the vitamin D activity of milk is in the aqueous fraction, the boys would have been getting considerably more vitamin D than the results suggested, and their average intake may have been about 3-5mug/d. 3. It was not possible to make any quantitative measure of the exposure of the boys to sunlight. All Asian boys studied appeared to have their bodies more completely covered than British or West Indian boys. 4. The problem of why nine boys had signs of rickets and nine had none has not been solved. It is suggested that those with signs of rickets may have had higher requirements for vitamin D than others. When the intake of vitamin D is low and exposure to sunlight is minimal, those with high requirements will be the ones to develop signs of rickets.