Children born to mothers with inadequate vitamin D-serum 25(OH)D levels were more likely to have suboptimal gross-motor skills when compared with children born to mothers with adequate levels, according to research recently published in the British Journal of Nutrition.
“Few human studies have assessed the relationship between maternal vitamin D status and neurodevelopmental outcomes,” Andrea L. Darling, BSc (Hons) PhD, from the department of nutritional sciences at the University of Surrey, England, and colleagues wrote. “The results of the five [previously] published observational studies that exist are inconsistent.”
To gather more data, researchers studied data from 7,065 mother-child pairs from the Avon Longitudinal Study of Parents and Children cohort who had data for both serum total 25(OH)D concentration in pregnancy and at least one of the following measures of their offspring’s neurodevelopment: preschool development at 6 to 42 months; Strengths and Difficulties Questionnaire scores at 7 years; intelligence quotient at 8 years; or reading ability at 9 years.
Darling and colleagues found that mothers with vitamin D levels of less than 50 nmol/L were more likely to have children with scores in the lowest quartile for gross-motor development at 30 months (OR = 1.2; 95 % CI, 1.03–1.4), fine-motor development at 30 months (OR = 1.23; 95% CI, 1.05–1.44) and social development at 42 months (OR = 1.2; 95% CI, 1.01–1.41) than mothers whose vitamin D levels were 50 nmol/L or greater. In addition, the researchers found that deficient maternal vitamin D status in pregnancy may have adverse effects on some measures of motor and social development in children less than 4 years of age.
Researchers also stated that no associations were found with neurodevelopmental outcomes, including intelligence quotient, when measured at older ages.
According to Darling and colleagues, these data reflect adjustments made for breast-feeding, number of people in the residence, housing status, mother’s education level, her ethnicity, the child’s sex, mother’s iodine/creatinine ratio, oily fish intake per week, parity, season of vitamin D measure, smoking status and social class.
“There is a need for replication of this work in other settings to confirm these results, but the public-health implications of these findings are nevertheless potentially important,” researchers wrote. “Further study is now urgently required, particularly in population groups that are more severely vitamin D deficient such as dark-skinned ethnic-minority women whose children may show a wider range and greater severity of suboptimal neurocognitive outcomes.”
Primary care physicians should note that when advising patients who need more vitamin D in their diet, previously published research has suggested that vitamin D3 may be better than vitamin D2 for preventing deficiency. – by Janel Miller
Darling reports no relevant financial disclosures. Please see the study for a full list of the author’s relevant financial disclosures.