Table 4. Associations of maternal 25-hydroxyvitamin D concentrations in pregnancy with offspring cognitive performance during childhood.
| Cognitive function tests | |||||||
|---|---|---|---|---|---|---|---|
| Maternal vitamin D concentrations | N | Learning, long-term retrieval | Short-term Memory | Reasoning Ability | Verbal Fluency | Visuo-spatial Ability | Attention and concentration |
| Vitamin D status | Score | ||||||
| Normal (>50 nmol/L) | 155 | 68.7 ± 17.8 | 16.5 ± 2.5 | 10.0 (4.0, 15.0) | 16.4 ± 5.4 | 77.5 (63.0, 89.3) | 33.2 ± 9.1 |
| Low (<50 nmol/L) | 313 | 67.8 ± 17.3 | 16.5 ± 2.6 | 10.0 (5.0, 13.0) | 16.1 ± 4.8 | 76.9 (63.7, 88.4) | 32.7 ± 7.8 |
| P† | 0.6 | 0.9 | 0.7 | 0.6 | 0.9 | 0.5 | |
| β (95% CI)‡ | |||||||
| Model 1 | 468 | -0.03 (-0.23, 0.17) | 0.04 (-0.15, 0.24) | -0.005 (-0.20, 0.19) | -0.01 (-0.20, 0.18) | -0.001 (-0.19, 0.19) | 0.03 (-0.16, 0.21) |
| Model 2 | 468 | 0.01 (-0.20, 0.21) | 0.05 (-0.16, 0.25) | 0.003 (-0.20, 0.20) | -0.02 (-0.22, 0.18) | 0.03 (-0.16, 0.23) | 0.002 (-0.19, 0.19) |
| Model 3 | 465 | -0.04 (-0.24, 0.15) | 0.01 (-0.19, 0.21) | -0.04 (-0.23, 0.16) | -0.04 (-0.25, 0.16) | 0.02 (-0.18, 0.21) | 0.04 (-0.15, 0.22) |
| Vitamin D quartiles | Score | ||||||
| < 23.5 nmol/L | 121 | 68.3 ± 16.7 | 16.5 ± 2.6 | 10.0 (6.0, 13.0) | 15.6 ± 4.3 | 77.6 (63.7, 87.8) | 32.7 ± 7.9 |
| 23.6 – 38.9 nmol/L | 113 | 67.7 ± 17.2 | 16.3 ± 2.4 | 10.0 (4.0,14.0) | 16.3 ± 5.1 | 75.0 (63.1, 89.2) | 32.0 ± 8.1 |
| 39.0 – 57.0 nmol/L | 116 | 68.9 ± 17.4 | 16.8 ± 2.9 | 11.0 (7.0,14.0) | 16.3 ± 4.9 | 76.8 (66.3, 88.2) | 33.4 ± 7.7 |
| >57.0 nmol/L | 118 | 67.4 ± 18.7 | 16.5 ± 2.4 | 10.0 (4.0,14.0) | 16.6 ± 5.6 | 77.5 (62.0, 90.2) | 33.3 ± 9.3 |
| P for trend§ | 0.7 | 0.9 | 0.2 | 0.6 | 0.9 | 0.7 | |
| β (95% CI)¶ | |||||||
| Model 1 | 468 | -0.02 (-0.11, 0.07) | -0.01 (-0.10, 0.09) | -0.06 (-0.15, 0.04) | 0.02 (-0.07, 0.12) | 0.008 (-0.08, 0.10) | -0.02 (-0.11, 0.07) |
| Model 2 | 468 | -0.03 (-0.13, 0.06) | -0.01 (-0.11, 0.09) | -0.06 (-0.16, 0.03) | 0.03 (-0.07, 0.12) | -0.006 (-0.10, 0.09) | -0.01 (-0.10, 0.08) |
| Model 3 | 465 | -0.01 (-0.11, 0.08) | 0.005 (-0.09, 0.10) | -0.05 (-0.14, 0.04) | 0.04 (-0.05, 0.14) | 0.002 (-0.09, 0.09) | -0.02 (-0.11, 0.07) |
Values are mean ± SD or medians (inter quartile range) unless otherwise stated
P value for the difference in cognitive test scores between children of mothers with normal and low 25-hydroxyvitamin D concentrations derived using t test
β (SD) is the difference in cognitive test score between children of mothers with normal and low 25-hydroxyvitamin D concentrations
P for trend adjusted for the child’s sex and current age derived by multiple linear regression using 25-hydroxyvitamin D concentrations as a continuous variable
β is the effect size (SD) of the cognitive test score per SD change in 25-hydroxyvitamin D concentrations (used as a continuous variable) derived by multiple linear regression
Model 1: adjusted for the child’s sex and current age
Model 2: Model 1 + season at the time of blood sampling
Model 3: Model 2 + gestational age, the child’s birthweight, head circumference at birth, weight, length and head circumference at age 2 years, current BMI and head circumference, maternal age, parity, standard of living index, maternal and paternal education, maternal intelligence (imputed) and home environment (imputed)