Table 3. Associations of covariates or confounders with cognitive outcomes and maternal 25-hydroxyvitamin D concentrations†.
| Learning, long-term retrieval | Short-term memory | Reasoning ability | Verbal fluency | Visuo-spatial ability | Attention and concentration | Maternal 25-hydroxy vitamin D concentrations | |
|---|---|---|---|---|---|---|---|
| Covariates/confounders | β (95% CI) |
β (95% CI) |
β (95% CI) |
β (95% CI) |
β (95% CI) |
β (95% CI) |
β (95% CI) |
| Maternal age (years) | 0.26 (-0.11, 0.63) |
0.06 (0.004, 0.11)* |
0.03 (0.01, 0.06)** |
0.01 (-0.09, 0.12) |
0.04 (0.02, 0.06)*** |
0.17 (0.01, 0.33)* |
0.01 (-0.004, 0.02) |
| Maternal parity (0, 1 and ≥2) | -2.56 (-4.41, -0.71)** |
-0.35 (-0.62, -0.07)* |
-0.15 (-0.27, -0.04)** |
-0.36 (-0.87, 0.15) |
0.04 (-0.14, 0.07) |
-0.01 (-0.83, 0.81) |
0.06 (-0.01, 0.13) |
| Birthweight (kg) | 3.09 (-0.66, 6.84) |
0.23 (-0.33, 0.78) |
0.16 (-0.07, 0.39) |
-0.19 (-1.22, 0.84) |
0.30 (0.09, 0.51)** |
1.30 (-0.35, 2.95) |
-0.08 (-0.23, 0.07) |
| Head circumference at birth (cm) | 1.86 (0.62, 3.11)** |
0.16 (-0.03, 0.34) |
0.05 (-0.02, 0.13) |
0.04 (-0.31, 0.38) |
0.09 (0.02, 0.16)* |
0.26 (-0.29, 0.82) |
-0.008 (-0.06, 0.04) |
| Weight at age 2 years (kg) | 2.31 (0.99, 3.64)** |
0.40 (0.20, 0.59)*** |
0.14 (0.07, 0.23)*** |
0.31 (-0.06, 0.67) |
0.11 (0.04, 0.19)** |
1.02 (0.45, 1.59)*** |
-0.001 (-0.05, 0.05) |
| Length at age 2 years (cm) | 1.02 (0.52, 1.52)*** |
0.15 (0.08, 0.23)*** |
0.07 (0.04, 0.10)*** |
0.15 (0.01, 0.29)* |
0.06 (0.03, 0.09)*** |
0.43 (0.21, 0.65)*** |
-0.003 (-0.02, 0.02) |
| Head circumference at age 2 years (cm) | 2.53 (1.35, 3.71)*** |
0.33 (0.16, 0.51)*** |
0.15 (0.08, 0.22)*** |
0.43 (0.10, 0.76)* |
0.11 (0.04, 0.18)** |
0.81 (0.29, 1.32)** |
-0.006 (-0.05, 0.04) |
| Child’s current BMI (kg/m2) | 1.58 (0.74, 2.43)*** |
0.18 (0.05, 0.30)** |
0.09 (0.04, 0.14)*** |
0.31 (0.07, 0.54)** |
0.04 (-0.01, 0.09) |
0.75 (0.38, 1.12)*** |
0.004 (-0.03, 0.04) |
| Child’s current head circumference (cm) | 2.37 (1.28, 3.46)*** |
0.38 (0.22, 0.53)*** |
0.15 (0.09, 0.22)*** |
0.41 (0.10, 0.71)** |
0.11 (0.05, 0.18)*** |
1.08 (0.60, 1.56)*** |
-0.008 (-0.05, 0.04) |
| Standard of living index (score) | 0.42 (0.23, 0.61)*** |
0.07 (0.04, 0.10)*** |
0.03 (0.02, 0.05)*** |
0.10 (0.05, 0.16)*** |
0.03 (0.02, 0.04)*** |
0.19 (0.10, 0.27)*** |
-0.004 (-0.01, 0.003) |
| Maternal education (completed years) | 1.06 (0.61, 1.51)*** |
0.22 (0.15, 0.28)*** |
0.09 (0.06, 0.11)*** |
0.25 (0.13, 0.37)*** |
0.09 (0.06, 0.11)*** |
0.44 (0.25, 0.64)*** |
-0.005 (-0.02, 0.01) |
| Paternal education (completed years) | 0.78 (0.43, 1.12)*** |
0.12 (0.07, 0.17)*** |
0.07 (0.04, 0.09)*** |
0.17 (0.08, 0.27)** |
0.06 (0.04, 0.08)*** |
0.35 (0.19, 0.50)*** |
0.008 (-0.006, 0.02) |
| Maternal intelligence (score) | 0.21 (0.12, 0.31)*** |
0.03 (0.02, 0.04)*** |
0.02 (0.01, 0.02)*** |
0.02 (-0.01, 0.05) |
0.01 (0.005, 0.02)*** |
0.05 (0.01, 0.09)* |
-0.0008 (-0.005, 0.003) |
| Home environment (score) | 0.58 (0.27, 0.89)*** |
0.08 (0.03, 0.12)*** |
0.06 (0.04, 0.08)*** |
0.18 (0.10, 0.27)*** |
0.04 (0.02, 0.06)*** |
0.36 (0.22, 0.49)*** |
-0.004 (-0.02, 0.01) |
†
Data presented for the participants during childhood
β is the effect size of the cognitive scores and maternal 25-hydroxy vitamin D concentrations per unit change in covariates/confounders, derived using multiple linear regression adjusted for the child’s sex and current age, and using all variables as continuous
*
P<0.05;
**
P<0.01;
***
P<0.001; P values derived by multiple linear regression adjusted for the child’s sex and current age