BBC Wales reports that cases of the crippling children's bone disease rickets are being seen in Cardiff. "Caused by a lack of vitamin D, the disease can lead to deformities like bowed legs and stunted growth, but it largely disappeared last century. Eye on Wales has learnt health professionals working in communities in south Cardiff are reporting incidents."
Vitamin D deficiency can result in a host of serious health conditions, including susceptibility to colds and flu, overweight and dental problems. See Vitamin D Deficiency. Sunshine is a good source of vitamin D. Food sources include oily fish such as salmon and sardines, eggs, full fat natural yoghurt, whole milk and beef liver. Low fat diets are not healthy, but they are particularly bad for children. Your doctor can arrange for vitamin D level testing.