Table 4.

Comparison of vitamin D serum levels (VDSL) in Varese study (V), Cattaruzza (C) and Nurnberg (N).

VDSL	M						C						p
	n			%			n			%
	V	C	N	V	C	N	V	C	N	V	C	N	V	C	N
≤ 20 ng/ml	76	91	160	49.4	66.2	78.1	24	15	89	19.2	15.2	63.1	< 0.001	< 0.001	< 0.001
> 20 ng/ml	78	46	45	50.6	33.8	22.0	101	84	52	80.8	84.8	36.9
≥ 30 ng/ml	22	10	–	14.3	7.3	–	61	37	–	48.8	37.4	-

Study	Mediancases (ng/ml)	Median controls (ng/ml)	p
Varese	20.3	29.5	< 0.0001
Cattaruzza	18.0	27.8	< 0.001
Nurnberg	16.9	18.8	0.44