Seasonal variability of serum 25-hydroxyvitamin D on multiple sclerosis onset

Vitamin D deficiency is associated with an increased risk of multiple sclerosis (MS). However, its effect on the age of disease onset remains unclear. This study examines the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and age of first symptom onset among recently diagnosed MS patients. Serum 25(OH)D was measured from forty MS patients sampled near disease onset. After correcting seasonal variability, the association between 25(OH)D levels, along with other clinical measures such as IgG index, and age at MS onset was examined using multivariable linear regression. Serum 25(OH)D was not correlated with age at onset (P > 0.5). We observed bias among previously reported associations between 25(OH)D and MS disease measures resulting from non-random distribution of sampling by season. After correcting for seasonal 25(OH)D and other clinical measures, only CSF IgG index remained significantly associated with age at disease onset (β = − 5.35, P = 0.028). In summary, we observed no association between age at onset and serum 25(OH)D levels but observed a negative correlation with CSF IgG index, although this will require further investigation.

[Association of vitamin D metabolism enzyme gene polymorphisms with multiple sclerosis risk: pilot study]

OBJECTIVE

To evaluate the association polymorphisms in genes coding for enzymes involved in vitamin D metabolism CYP27B1 (rs703842) and CYP24A1 (rs2248359) with the risk of multiple sclerosis (MS).

MATERIAL AND METHODS

Ninety Caucasian patients with remitting MS and 87 volunteers without MS, born and living in the Altai region of Russia, participated in the study. Genotyping was performed by the TaqMan probe method.

RESULTS

No association of MS with genotypes or alleles of CYP24A1 (rs2248359) is found. CYP27B1C (rs703842) is associated with the risk of MS in women. The TC genotype CYP27B1C (rs703842) is associated with an increased risk of MS (Odd Ratio 3.43; 1.48-7.93, p=0.004), while the TT genotype, on the contrary, has a protective effect on the susceptibility to MS (Odd Ratio 0.31; 0.14-0.72, p=0.005).

CONCLUSION

The results indicate an increased risk of MS in female carriers of the TC genotype CYP27B1 (rs703842) and a low probability of the contribution of the CYP24A1 polymorphism (rs2248359) to the predisposition to MS in Caucasians of the Altai region.