Lack of vitamin D may 'raise dementia risk'

People lacking in vitamin D have a higher risk of developing dementia report several media outlets, including BBC News and The Independent.

A study found people severely lacking in the sunshine vitamin were twice as likely to develop dementia and Alzheimer's disease compared with people with healthy levels (50nmol/l or more).

The findings are based on a study of more than 1,650 people aged 65 and above who were followed over a period of about six years to see if they developed dementia.

Researchers found the higher the vitamin D deficiency, the higher the risk of developing dementia and Alzheimer's disease.

They found severe vitamin D deficiency (less than 25nmol/l) is associated with approximately twice the risk of developing dementia or Alzheimer's disease.

Moderately low levels of vitamin D (between 25nmol/l and 50nmol/l) are associated with a 50% increase in risk.

This study was able to show an association between low levels of vitamin D and the risk of developing dementia. But it does not prove that vitamin D deficiency causes the disease.

Other factors that can increase the risk of developing dementia, including a poor diet, lack of activity and general poor health, can also cause a low vitamin D level.

More research is needed to establish whether eating vitamin D-rich foods, such as oily fish, or taking vitamin D supplements could delay or even prevent dementia.