Table 3. Association between mid-gestation and cord 25OHD deficiency and Social Responsiveness Scale.

		N	B (s.e.)	χ2(1)	p
A	Mid-gestation - 25OHD deficient vs sufficient	2 866	0.06 (0.01)	25.53	<0.001***
	Mid-gestation - 25OHD insufficient vs sufficient	3 237	0.02 (0.01)	6.89	0.007**
	Cord - 25OHD deficient vs sufficient	1 712	0.03 (0.01)	6.77	0.01*
	Cord - 25OHD insufficient vs sufficient	1 819	0.02 (0.01)	3.09	0.08
B	Mid-gestation and Cord 25OHD deficient vs Mid-gestation and Cord 25OHD sufficient	1 810	0.07 (0.02)	12.19	<0.001***
	Mid-gestation or Cord 25OHD deficient vs Mid-gestation and Cord 25OHD sufficient	2 197	0.01 (0.01)	1.52	0.26
C	Mid-gestation - 25OHD	3 861	-0.07 (0.01)	19.74	<0.001***
	Cord - 25OHD	2 847	-0.05 (0.02)	9.99	0.002**

Notes: Panel A: One time-point analyses: association between 25OHD deficiency and Social Responsiveness Scale for 25OHD categories from midgestation and neonatal samples; Panel B: Two time-point analyses: association between mid-gestation and cord 25OHD deficiency and Social Responsiveness Scale; Panel C: 25OHD analyses as a continuous measure; for all analyses presented in Panel A, B, and C, estimates are based on a mixed linear model; family membership was fitted as a random effect in the model; N = sample size, β = effect size; s.e. = standard error; X²(1) = chi-squared test statistic with 1 degree of freedom; p = p-value;

^*= significant at α of 0.05;

^**= significant at α of 0.01;

^***= significant at α of 0.001; covariates included in the model are: ethnicity of child; sex child, age child at time of SRS assessment, birth weight child, gestational age at time of birth, age mother at intake, age father at intake, smoking mother during pregnancy, educational level mother, and BMI mother at mid-gestation; For the analyses presented in Panels A and B, i.e., 25OHD concentrations are categorized into three categories: Sufficient, Insufficient, and Deficient, positive beta values imply an association between more deficient categories of 25OHD concentrations and increase (more impaired) scores on the SRS; For the analyses presented in Panel C, i.e., 25OHD concentrations are treated as continuous measures in the analyses, negative beta values imply an association between lower concentrations of 25OHD and increased (more impaired) scores on the SRS; 25OHD concentrations more than 5 standard deviations above the mean were winzorised, this is 25OHD > 150 nmol/L for Mid-gestation samples (n=4) and 25OHD > 100 nmol/L for Cord samples (n=20), 25OHD measures were log-transformed; results of statistically significant analyses (α < 0.05) are presented in bold font.