Table 1. Study population characteristics in relation to lifetime maternal history of diagnosed vitamin D deficiency.

	Maternal history of vitamin D deficiency
Characteristic	No	Yes	P	All
Individuals, n (%)	509 092 (99.9)	547 (0.1)		509 639 (100.0)
Cases of ASD with intellectual disability, n (%)	2463 (0.5)	13 (2.4)	<0.0001	2476 (0.5)
Cases of ASD without intellectual disability, n (%)	7396 (1.4)	10 (1.8)	0.46	7406 (1.4)
Male (%)	51.3	52.6	0.51	51.3
Maternal age, years: mean	29.9	28.5	<0.0001	29.9
Paternal age, years: mean	32.8	34.0	<0.0001	32.8
Maternal country of birth (%)
Sweden	76.3	19.2	<0.0001	76.2
Europe	8.3	4.6	0.002	8.3
Outside Europe	12.8	38.9	<0.0001	12.9
Sub-Saharan Africa	2.6	37.3	<0.0001	2.6
Lowest quintile of disposable family income (%)	14.8	35.6	<0.0001	14.8
Elementary maternal education (%)	15.6	43.1	<0.0001	15.6
Elementary paternal education (%)	16.8	32.7	<0.0001	16.8
Born small for gestational age (%)	2.5	3.7	0.09	2.5
Premature birth (<37 weeks, %)	5.9	6.2	0.07	5.9
Maternal history of neuropsychiatric disorder (%)a	2.4	9.3	<0.0001	2.4
Paternal history of neuropsychiatric disorder (%)a	2.0	2.0	0.98	2.0
Maternal history of affective disorder (%)b	15.4	36.8	<0.0001	15.4
Paternal history of affective disorder (%)b	8.1	10.8	0.02	8.1
Maternal history of epilepsy (%)	1.0	1.5	0.25	1.0
Paternal history of epilepsy (%)	1.0	0.7	0.52	1.0

^aParental histories of neuropsychiatric disorder include any in-patient or secondary care out-patient record of diagnosed non-affective psychosis, bipolar disorder, attention-deficit hyperactivity disorder, ASD, or intellectual disability.

^bParental histories of affective disorder include any in-patient or secondary care out-patient record of diagnosed affective disorder except for bipolar disorder.

ASD, autism spectrum disorder.