As the condition gets worse, pain can be felt everywhere and any movement can be painful.
A lack of vitamin D, calcium or phosphorus means that mineralisation doesn’t take place normally, and weak, soft bones are created. This is osteomalacia.
There are different forms of vitamin D and research is investigating whether one form is more effective than another.
Leading medical research charity Arthritis Research UK is using the first day of British Summer Time to remind groups at risk of vitamin D deficiency to beat Britain’s grey skies and top up their levels of the essential ‘sunshine’ vitamin.