Table 2.

Serum vitamin D status in subjects with autoimmune diseases

	Author	Year	Disease subject	Healthy control	Result	Ref. no.
Multiple sclerosis	Hiremath et al.	2009	199	/	Large numbers (84 %) of MS patients had insufficient levels (≤100 nmol/L) of 25(OH)D.	[76]
	Correale et al.	2009	132	60	Serum 25(OH)D and 1,25(OH)2D levels were lower in MS patients. The levels were lower during MS relapses than remission.	[72]
	Kragt et al.	2009	103	110	Higher circulating levels of 25(OH)D were associated with a lower incidence of MS.	[78]
	Smolders et al.	2008	267	/	Low serum 25(OH)D levels were associated with high disability and relapse rate in MS patients.	[75]
	Soilu-Hanninen et al.	2008	23	23	Seasonal variation of 25(OH)D was similar in MS patients and controls, but 25(OH)D serum levels were lower during MS relapses than in remission.	[73]
	van der Mei et al.	2007	136	272	Vitamin D insufficiency was only observed in MS patients with higher disability but not in those with lower disability.	[74]
	Munger et al.	2006	257	514	High circulating levels of 25(OH)D were associated with a lower risk of MS among whites but not blacks and Hispanics.	[77]
	Soilu-Hanninen et al.	2005	40	40	Serum 25(OH)D concentrations were lower in MS patients from June to September. The levels were lower during MS relapses than remission.	[71]
Type 1 diabetes mellitus	de Boer et al.	2012	1193	/	Low plasma concentrations of 25(OH)D and 24,25(OH)2D were associated with increased risk of microalbuminuria in T1DM.	[79]
	Borkar et al.	2010	50	50	Plasma 25(OH)D levels were lower in T1DM children. Vitamin D deficiency was higher in T1DM children compared to controls.	[80]
	Singh et al.	2009	40	41	Serum 1,25(OH)2D levels were lower in T1DM patients compared to controls.	[81]
	Bener et al.	2009	170	170	Vitamin D deficiency was higher in T1DM children compared to non-diabetic.	[82]
	Littorin et al.	2006	138	208	Plasma 25(OH)D levels were lower in T1DM patients than in control subjects. The levels were lower in men than in women with T1DM.	[83]
Systemic lupus erythematosus	Bogaczewicz et al.	2012	49	49	Serum 25(OH)D concentrations were lower in SLE patients only during the warm season. The cold season was found to be a risk factor for vitamin D deficiency.	[84]
	Kim et al.	2010	104	49	Serum 25(OH)D levels were lower and vitamin D insufficiency was more common in SLE patients. Vitamin D levels had no relation with SLE severity.	[85]
	Amital et al.	2010	378	/	Vitamin D serum concentrations were found to be inversely related to SLE activity.	[86]
	Wright et al.	2009	38	207	Severe deficiency (≤10 ng/mL) of 25(OH)D was more frequent among subjects with SLE. 25(OH)D and 1,25(OH)2D were both lower in SLE.	[87]
	Borba et al.	2009	36	26	A high prevalence of 25(OH)D deficiency was observed in SLE patients. Low levels of 25(OH)D were present in patients in overt disease and negatively related to disease activity.	[88]
	Ruiz-Irastorza et al.	2008	92	/	Vitamin D insufficiency and deficiency were common in SLE patients. Vitamin D levels had no relation with SLE severity.	[89]