From my quick skim of the article, I think this is the key part:
> These results imply that, after correcting for confounding variables (see notes under Table 3), those who were deficient at time of birth had on average 0.06 point higher gender-weighted SRS score, which corresponds to an increase of approximately one fourth of the s.d. (s.d. of the SRS in the total sample=0.23). When treating SRS as a dichotomous outcome, that is, comparing children with SRS scores above the suggested cutoff with children below the suggested cutoff, those who were vitamin D deficient at mid-gestation were 3.8 times more likely to be screened positive than those who were vitamin D sufficient at mid-gestation (see also Supplementary Table 4).
> These results imply that, after correcting for confounding variables (see notes under Table 3), those who were deficient at time of birth had on average 0.06 point higher gender-weighted SRS score, which corresponds to an increase of approximately one fourth of the s.d. (s.d. of the SRS in the total sample=0.23). When treating SRS as a dichotomous outcome, that is, comparing children with SRS scores above the suggested cutoff with children below the suggested cutoff, those who were vitamin D deficient at mid-gestation were 3.8 times more likely to be screened positive than those who were vitamin D sufficient at mid-gestation (see also Supplementary Table 4).
(SRS is the Social Responsiveness Scale)