The reason I have stuck with this with you is because it was thoroughly investigated by my son and the sports doctors when his son's arm broke twice with greenstick fractures. He is on the list of professional young tennis players and the sports doctors were documenting this in an effort to help the grandson and the rest of their players.
It was the sports doctors who first set up his going to Spain and staying a while for sun with adult players in Spain. He has gone there several times for sun.
The best thing England could do is put Vitamin D in the milk for children like we do - instead they have to drink certain fish oil.
The Vitamin D they put in milk in the U.S. usually IS fish oil.
Since England has NEVER put Vitamin D in milk, how is it that the rates of deficiency has gone UP, way up? Something must have changed.