Table 5. Associations of maternal 25-hydroxyvitamin D concentrations in pregnancy with offspring cognitive performance during adolescence.
| 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) | 152 | 80.3 ± 15.7 | 19.1 ± 4.0 | 16.4 ± 7.0 | 21.7 ± 5.8 | 85.5 ± 25.3 | 48.6 ± 12.1 |
| Low (<50 nmol/L) | 320 | 79.9 ± 14.0 | 19.0 ± 3.7 | 15.3 ± 6.4 | 21.1 ± 5.7 | 83.0 ± 26.1 | 47.5 ± 10.4 |
| P† | 0.7 | 0.8 | 0.1 | 0.3 | 0.3 | 0.3 | |
| β (95% CI)‡ | |||||||
| Model 1 | 472 | -0.02 (-0.21, 0.18) | -0.01 (-0.21, 0.18) | -0.14 (-0.34, 0.05) | -0.09 (-0.29, 0.10) | -0.08 (-0.28, 0.11) | -0.07 (-0.25, 0.12) |
| Model 2 | 472 | 0.06 (-0.14, 0.27) | 0.02 (-0.18, 0.22) | -0.07 (-0.28, 0.13) | -0.14 (-0.33, 0.06) | -0.08 (-0.28, 0.12) | -0.11 (-0.30, 0.08) |
| Model 3 | 472 | 0.04 (-0.17, 0.24) | 0.01 (-0.20, 0.21) | -0.10 (-0.28, 0.10) | -0.12 (-0.32, 0.08) | -0.08 (-0.28, 0.12) | -0.07 (-0.26, 0.12) |
| Vitamin D quartiles | Score | ||||||
| < 23.5 nmol/L | 123 | 80.9 ± 13.4 | 19.2 ± 3.7 | 15.4 ± 6.4 | 20.7 ± 5.3 | 82.3 ± 26.1 | 47.7 ± 10.6 |
| 23.6 – 38.9 nmol/L | 118 | 79.0 ± 13.7 | 18.7 ± 3.7 | 14.8 ± 6.6 | 20.8 ± 6.1 | 83.6 ± 26.1 | 46.5 ± 11.0 |
| 39.0 – 57.0 nmol/L | 116 | 80.0 ± 15.0 | 19.0 ± 3.8 | 16.2 ± 6.6 | 22.1 ± 5.7 | 83.5 ± 25.3 | 48.9 ± 10.6 |
| >57.0 nmol/L | 115 | 79.8 ± 16.2 | 19.1 ± 4.1 | 16.3 ± 7.1 | 21.8 ± 5.8 | 86.0 ± 26.0 | 48.3 ± 11.8 |
| P for trend§ | 0.7 | 0.7 | 0.7 | 0.08 | 0.6 | 0.9 | |
| β (95% CI)¶ | |||||||
| Model 1 | 472 | -0.02 (-0.11, 0.08) | -0.02 (-0.11, 0.07) | 0.02 (-0.07, 0.11) | 0.08 (-0.01, 0.17) | 0.03 (-0.07, 0.12) | 0.003 (-0.08, 0.09) |
| Model 2 | 472 | -0.05 (-0.15, 0.04) | -0.04 (-0.13, 0.06) | -0.01 (-0.11, 0.08) | 0.10 (0.01, 0.19)* | 0.02 (-0.07, 0.12) | 0.02 (-0.07, 0.11) |
| Model 3 | 472 | -0.02 (-0.11, 0.08) | -0.02 (-0.12, 0.07) | 0.01 (-0.08, 0.10) | 0.10 (0.01, 0.20)* | 0.03 (-0.07, 0.12) | 0.02 (-0.07, 0.11) |
Values are mean ± SD 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)
P<0.05; P values derived by multiple linear regression