Department of Global Public Health and Primary Care

Vitamin D intake and MS risk: Is timing important?

Vitamin D, consumed via oily fish or cod liver oil supplements, may lower the risk of adult-onset multiple sclerosis (MS). Adolescence may be a particularly susceptible life period for such vitamin D-based risk reduction.

Cod liver oil - illustration: Colourbox
Illustration: Colourbox

Main content

Multiple Sclerosis (MS) affects more than 2-5 million people around the world. It is an unpredictable, often disabling disease of the central nervous system that disrupts the flow of information within the brain, and between the brain and body.

Four researchers from the Lifestyle Epidemiology research group at the Department of Global Public Health and Primary Care (IGS) at the University of Bergen (UiB) were involved in the study. These included PhD student Marianna Cortese, Professor Trond Riise, PhD student Kjetil Bjørnevik and Professor Maura Pugliatti.

Norwegians need vitamin D supplements

Low levels of vitamin D are one of the factors most consistently associated with an increased risk of MS. The levels of vitamin D circulating in our blood are influenced by sun exposure and diet. In northerly latitude countries, such as Norway, there is no sun-induced vitamin D production in the winter. Traditionally Norwegians supplement their diet with vitamin D-rich fatty fish and cod liver oil to ensure adequate vitamin D levels.

Is timing important?

The study investigated different life periods to determine whether the timing of supplementation had different effects on the risk of developing adult-onset MS. The different periods included childhood, adolescence (13-18 years) and adulthood.  The data were taken from the Norwegian component of a multinational case-control study on MS entitled, Environmental Factors In Multiple Sclerosis (EnvIMS). It involved a self-administered postal questionnaire. 

The results showed that adolescence seems to be an important susceptibility period.  Further analyses suggested that doses of 600-800 IU/d per day might have the strongest protective effect at that age. It is an exciting result and further research is needed to determine if higher doses might have the potential to give increased protection in other life periods as well. 

Read the paper:

Timing of use of cod liver oil, a vitamin D source, and multiple sclerosis risk: The EnvIMS study.              

Cortese M, Riise T, Bjørnevik K, Holmøy T, Kampman MT, Magalhaes S, Pugliatti M, Wolfson C, Myhr KM. Mult Scler. 2015 May