Is low vitamin D a cause of multiple sclerosis?

 Mendelian randomization shows a causal effect of low vitamin D on multiple sclerosis risk

Rhead B, Bäärnhielm M, Gianfrancesco M, et al.

Neurol Genet 2016; 2:e97.

Abstract

OBJECTIVE:

We sought to estimate the causal effect of low serum 25(OH)D on multiple sclerosis (MS) susceptibility that is not confounded by environmental or lifestyle factors or subject to reverse causality.

METHODS:

We conducted mendelian randomization (MR) analyses using an instrumental variable (IV) comprising 3 single nucleotide polymorphisms found to be associated with serum 25(OH)D levels at genome-wide significance. We analyzed the effect of the IV on MS risk and both age at onset and disease severity in 2 separate populations using logistic regression models that controlled for sex, year of birth, smoking, education, genetic ancestry, body mass index at age 18-20 years or in 20s, a weighted genetic risk score for 110 known MS-associated variants, and the presence of one or more HLA-DRB1*15:01 alleles.

RESULTS:

Findings from MR analyses using the IV showed increasing levels of 25(OH)D are associated with a decreased risk of MS in both populations. In white, non-Hispanic members of Kaiser Permanente Northern California (1,056 MS cases and 9,015 controls), the odds ratio (OR) was 0.79 (p = 0.04, 95% confidence interval (CI): 0.64-0.99). In members of a Swedish population from the Epidemiological Investigation of Multiple Sclerosis and Genes and Environment in Multiple Sclerosis MS case-control studies (6,335 cases and 5,762 controls), the OR was 0.86 (p = 0.03, 95% CI: 0.76-0.98). A meta-analysis of the 2 populations gave a combined OR of 0.85 (p = 0.003, 95% CI: 0.76-0.94). No association was observed for age at onset or disease severity.

CONCLUSIONS:

These results provide strong evidence that low serum 25(OH)D concentration is a cause of MS, independent of established risk factors.

You may also check:

Past environmental sun exposure and risk of multiple sclerosis: a role for the Cdx-2 vitamin D receptor variant in this interaction.

Dickinson JL, Perera DI, van der Mei AF, et al.

Mult Scler 2009; 15:563-570.

Neonatal vitamin D status and risk of multiple sclerosis: a population-based case-control study.

Nielsen NM, Munger KL, Koch-Henriksen N, et al.

Neurology 2017; 88:44-51.

These references are now included in the neurochecklist:

Multiple sclerosis (MS): risk factors and prognosis

screen-shot-2016-12-24-at-23-32-53

Abstract link

https://pixabay.com/en/sunshine-abstract-sun-heat-warmth-151807/
https://pixabay.com/en/sunshine-abstract-sun-heat-warmth-151807/

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s