Dr Gillie said Scotland gets as little sunshine as some places in the Arctic
Scotland's poor health record could be directly linked to a lack of sunshine, a scientist has said.
Dr Oliver Gillie linked the "extreme" weather to vitamin D deficiency, which is caused by low exposure to sunlight.
He has called for "urgent" government action to encourage people to take a daily dose of vitamin D to help tackle diseases such as cancer and MS.
Scotland's chief medical officer said the Scottish Government was already considering the evidence on vitamin D.
Dr Gillie's research involved examining vitamin D levels across Europe and mortality rates from certain diseases.
Medics have already established a lack of the vitamin as a factor in conditions like heart disease and cancer, of which Scotland has some of the highest levels in Europe.
In his study, Dr Gillie called for "urgent action" by the Scottish Government.
This, he said, could include a campaign to encourage people to take a daily dose of the vitamin.
He also suggested that doctors should be able to prescribe stronger doses and that "megadoses" containing up to 50 times the current daily dose could be taken.
"Scotland has an extreme climate characterised by very little sunshine - it gets as little sunshine as some places in the Arctic Circle," he said.
"Its people have low levels of vitamin D because most vitamin D comes from the effect of sun on skin.
"Scots also have high levels of chronic illness - among the highest in the world.
"But vitamin D has received little or no attention from policy-makers in Scotland.
He called on ministers to introduce measures which would help Scotland catch up with other European countries which enjoy more favourable climates.
He said: "They need to revise advice to people.
"This is a problem that can be solved if they have got the political will to do it."
Placed in food
He added that vitamin D supplements could also be placed in foods such as bread, orange juice and milk.
"It also needs to be easier for GPs to prescribe vitamin D," he said.
"In France they take megadoses.
"This is something that could be considered and included in guidelines."
Chief medical officer, Dr Harry Burns, said Dr Gillie had made "an important contribution" to the debate on Scotland's health.
"The Scottish Government has already been considering the evidence on vitamin D and has already arranged a meeting of experts in the field for later this year to consider the significance of existing research and to recommend what further action is required," he said.
"It is important that attempts to improve health in Scotland remain focused on action on the social, economic, behavioural and psychological determinants of health.
"If vitamin D supplements can be shown to contribute to that agenda then we will make the appropriate recommendations."