Apparently cases of Rickets are on the rise in the UK. In 2011, there were 762 cases, up from 183 in 1995.
Rickets is caused by a deficiency of vitamin D. Vitamin D can come from dietary sources, or the human body can synthesize its own, in the presence of sunlight. It is thought that children spending less time outdoors and using more sunscreen could partially account for the increase in cases. Also, people of colour need more time in the sun in order to synthesize vitamin D, and an increase in people with darker skin in the UK may also be contributing to increasing incidence of Rickets.
Apparently, unlike Canada and the United States, the UK does not fortify milk and flour with vitamin D. One proposal to try and help fight Rickets is to hand out free vitamins to children under the age of 5.