Maternal Vitamin D Status and Adverse Birth Outcomes in Children from Rural Western Kenya

Abstract

Maternal plasma 25-hydroxyvitamin D (25(OH)D) status and its association with pregnancy outcomes in malaria holoendemic regions of sub-Saharan Africa is poorly defined. We examined this association and any potential interaction with malaria and helminth infections in an ongoing pregnancy cohort study in Kenya. The association of maternal plasma 25(OH)D status with pregnancy outcomes and infant anthropometric measurements at birth was determined in a subset of women (n = 63). Binomial and linear regression analyses were used to examine associations between maternal plasma 25(OH)D and adverse pregnancy outcomes. Fifty-one percent of the women had insufficient (<75 nmol/L) and 21% had deficient (<50 nmol/L) plasma 25(OH)D concentration at enrollment. At birth, 74.4% of the infants had insufficient and 30% had deficient plasma 25(OH)D concentrations, measured in cord blood. Multivariate analysis controlling for maternal age and body mass index (BMI) at enrollment and gestational age at delivery found that deficient plasma 25(OH)D levels were associated with a four-fold higher risk of stunting in neonates (p = 0.04). These findings add to the existing literature about vitamin D and its association with linear growth in resource-limited settings, though randomized clinical trials are needed to establish causation.

Keywords: Africa; malaria and helminth infections; maternal vitamin D status; pregnancy outcomes; stunting.

Figure 1

Maternal plasma 25(OH)D concentration over the gestation period visits and delivery (p > 0.05).

Figure 2

Maternal plasma 25(OH)D concentrations at enrollment (ANC-1), delivery (in venous), and cord blood by (a) maternal peripheral malaria infection at enrollment status; and by (b) maternal helminth or protozoan infection status at enrollment. Maternal malaria infection status was based on qPCR diagnosis at enrollment. Means were compared using t-test with significance set at p ≤ 0.05. Horizontal lines show plasma 25(OH)D levels for insufficiency (<75 nmol/L) and deficiency (<50 nmol/L).