Morning Extra - The Investigation — D is for Deficient

Is a lack of sunshine to blame for Scotland's poor health record? Scotland isn't known as the sick man of Europe for nothing. Heart disease, cancer, diabetes and the highest rate of Multiple Sclerosis in the world. But can we blame it on the weather? Is our relative lack of sunshine — and therefore lack of vitamin D — the cause? Elizabeth Quigley reports, and Graham Stewart takes your calls, texts and emails.