• Asian rickets;
  • vitamin D;
  • sunlight;
  • Pigmentation;
  • enterohepatic circulation;
  • Phytate;
  • cereals;
  • calcium metabolism disorders;
  • 25-hydroxyvitamin D;
  • hyperparathyroidism;
  • 1;
  • 25-dihydroxyvitamin D

A large body of work relating to the occurrence of rickets in UK Asians is reviewed. Several theories of the aetiology of this condition are shown to be untenable: it is not exclusively a function of sunlight deprivation or of darker pigmentation; nor is it simply due to phytate-induced losses of calcium from the gut. Asian rickets, however, is associated with a high consumption of cereals, and experiments with rats have suggested a mechanism. In the absence of adequate vitamin D from sunlight, the low-calcium, high cereal intake of the UK Asian population may induce a state of mild secondary hyperparathyroidism which enhances the destruction of vitamin D and leads to a progressive reduction in vitamin D status and, ultimately, to the development of clinical rickets.