Table 3. Comparison of vitamin D in Orkney and mainland Scotland by age group.

	N = Orkney; Scotland	Orkney mean crude 25(OH)D	Mainland mean crude 25(OH)D	t-test	p-value
< 40	46; 46	26.8	36.5	-2.67	0.009
40–49	263; 263	33.4	39.5	-3.13	0.002
50–59	399; 400	35.7	38.7	-1.97	0.049
60–69	466; 464	37.95	33.28	3.59	0.0004
70+	279; 280	38.51	30.39	4.84	1.6x10-6