The Impact of Prenatal and Postpartum Vitamin D Supplementation on Cholecalciferol Concentrations in Breast Milk
Open Access
- Author:
- Scott, Sarah
- Area of Honors:
- Nutritional Sciences
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Alison D Gernand, Thesis Supervisor
Alison D Gernand, Thesis Honors Advisor
Gregory C Shearer, Faculty Reader - Keywords:
- cholecalciferol
vitamin D supplementation
pregnancy
lactation
maternal
infant
Bangladesh - Abstract:
- Vitamin D deficiency is a global health issue which has been shown to impact pregnant and lactating mothers and their infants. Research has shown that maternal oral vitamin D supplementation can serve as a nutritional intervention to increase the vitamin D levels in mothers and infants. While previous studies show the impacts of vitamin D supplementation during pregnancy or lactation on breast milk vitamin D, there is limited research on supplementation during both time periods. Our goal was to examine the impact of maternal oral vitamin D supplementation during pregnancy and continued from pregnancy throughout lactation on maternal breast milk cholecalciferol. This thesis is a sub-study of the Maternal Vitamin D for Infant Growth (MDIG) trial conducted in Dhaka, Bangladesh where vitamin D deficiency is prevalent. The parent trial randomized 1124 pregnant women into five treatment groups (placebo (n=223), prenatal 4200IU/week (n=229), prenatal 16000IU/week (n=224), prenatal 28000IU/week (n=221), and prenatal and postpartum 28000IU/week (n=227). Our study included a sample of 71 pregnant women from three original treatment groups: placebo (n=24), prenatal 28000IU/week (n=23), and prenatal and postpartum 28000IU/week (n=24). The average maternal age was 23.9 ± 4.8 years old and average gestational age of infants at birth was 39.0± 1.4 weeks. For aim 1, we measured the concentration of cholecalciferol in the maternal breast milk samples at 6 months. The mean cholecalciferol concentrations were 14.0 nmol/L for the entire analytical sample, 16.8 nmol/L for the placebo group, 10.9 nmol/L for the pregnancy supplementation group, and 14.1 nmol/L for the prenatal and postpartum supplementation group. An ANOVA test determined no difference between groups (p=0.6299). For aim 2, we examined the relationships between maternal serum 25(OH)D levels with maternal breast milk cholecalciferol and maternal breast milk cholecalciferol with infant serum 25(OH)D. Twenty-eight infants and 25 mothers had serum 25(OH)D data available for analysis. Linear regression models were adjusted for infant sex, birth mode, parity, maternal age, and gestational age. Maternal serum 25(OH)D was not significantly associated with breast milk cholecalciferol concentration (unadjusted model: p-value =0.06; adjusted model: p-value = 0.07). Breast milk cholecalciferol was positively associated with infant serum 25(OH)D in both the unadjusted (p-value = 0.02) and adjusted (p-value = 0.03) models. In conclusion, we found that breast milk cholecalciferol did not increase with maternal vitamin D supplementation. However, evidence that infant serum 25(OH)D levels are associated with maternal milk cholecalciferol levels shows the importance of vitamin D in milk. Further studies should continue to examine the relationships between serum vitamin D levels with milk cholecalciferol, as well as the continuation of prenatal vitamins through lactation.