Table 4.

Vitamin D status and multiple sclerosis — evidence from Mendelian randomization studies

Study and ref.	Genesa	Number of controls; number of cases	Outcome	Estimate of effect (OR and 95% CI)	P value	Unit of estimated effect
Mokry et al.96	DHCR7, CYP2R1, GC and CYP24A1	38,589; 14,498	Multiple sclerosis	2.02 (1.65–2.46)	7.7 × 10−12	One standard deviation decrease in log-transformed 25OHD level
Rhead et al.99	DHCR7, CYP2R1 and GC	22,168; 7,391	Multiple sclerosis	0.85 (0.76–0.94)	0.003	Unit change in polygenic risk score
Jacobs et al.97	CYP2R1, DHCR7, CYP24A1, SEC23A and AMDHD1	41,505; 14,802	Multiple sclerosis	0.57 (0.41–0.81)	0.001	One unit increase in natural log-transformed vitamin D level
Gianfrancesco et al.98	GC, CYP2R1 and DHCR7	1,715; 34	Paediatric-onset multiple sclerosis	0.72 (0.55–0.94)	0.02	NA

25OHD, 25-hydroxyvitamin D; NA, not applicable. ^aGenes in which variants can be used to infer serum 25OHD concentration.