The Implications of Vitamin D Status During Pregnancy on Mother and her Developing Child

Abstract

Pregnancy is a time of tremendous growth and physiological changes for mother and her developing fetus with lifelong implications for the child. The concert of actions that must occur so mother does not reject the foreign tissue of the fetus is substantial. There must be exquisite balance between maternal tolerance to these foreign proteins of paternal origin but also immune surveillance and function such that the mother is not immunocompromised. When this process goes awry, the mother may experience such pregnancy complications as preeclampsia and infections. Vitamin D deficiency affects these processes. Controversy continues with regard to the optimal daily intake of vitamin D, when sunlight exposure should be taken into account, and how to define sufficiency during such vulnerable and critical periods of development. The importance of vitamin D supplementation during pregnancy in preventing some of the health risks to the mother and fetus appears linked to achieving 25(OH)D concentrations >40 ng/mL, the beginning point of the plateau where conversion of the vitamin D metabolite 25(OH)D, the pre-hormone, to 1,25(OH)2D, the active hormone, is optimized. Throughout pregnancy, the delivery of adequate vitamin D substrate—through sunlight or supplement—is required to protect both mother and fetus, and when in sufficient supply, favorably impacts the epigenome of the fetus, and in turn, long term health. There is a growing need for future research endeavors to focus not only on critical period(s) from pre-conception through pregnancy, but throughout life to prevent certain epigenetic changes that adversely affect health. There is urgency based on emerging research to correct deficiency and maintain optimal vitamin D status. The impact of vitamin D and its metabolites on genetic signaling during pregnancy in both mother and fetus is an area of great activity and still in its early stages. While vitamin D repletion during pregnancy minimizes the risk of certain adverse outcomes (e.g., preterm birth, asthma, preeclampsia, and gestational diabetes), the mechanisms of how these processes occur are not fully understood. As we intensify our research efforts in these areas. it is only a matter of time that such mechanisms will be defined.

Maternal plasma proteomics in a rat model of pregnancy complications reveals immune and pro‐coagulant gene pathway activation

“…41,42 Altogether, we speculate that the BN rat could be a useful model to investigate the relationships between vitamin D deficiency during pregnancy, the increase in maternal pro-inflammatory cytokines, and the development of pregnancy disorders such as hypertension, proteinuria, and placental insufficiency. The changes of key proteins identified in the DIGE/MS and IPA analysis were studied in age-matched female rats starting at non-pregnancy (NP) and throughout pregnancy days 9, 13, 17, and 21 (n = 4/rat strain per gestational age; total 20/rat strain).…”

“…7 BN dams show a drastic fivefold drop in the levels of bioactive vitamin D, and supplementation with calcitriol significantly improved fetal/placental weights and fetal viability as shown by litter sizes at birth. 7 This is of great interest, as maternal vitamin D deficiency has also been associated with pre-eclampsia and fetal-origins of postnatal asthma 41,42. Altogether, we speculate that the BN rat could be a useful model to investigate the relationships between vitamin D deficiency during pregnancy, the increase in maternal pro-inflammatory cytokines, and the development of pregnancy disorders such as hypertension, proteinuria, and placental insufficiency.…”

Targeting Vitamin D Deficiency to Limit Exacerbations in Respiratory Diseases: Utopia or Strategy With Potential?

“…Whether vitamin D intake during pregnancy has an impact on the development of childhood asthma is unclear as one metaanalysis found no significant association between prenatal vitamin D status and risk of asthma. However, recently, it was suggested that lower maternal vitamin D intake during pregnancy is associated with increased risk of children wheezing and being diagnosed with asthma in the first 10 years [96], indicating a role for vitamin D in the development of childhood asthma.…”

Perinatal Undernutrition, Metabolic Hormones, and Lung Development

“…The maternal calcitriol deficiency during lung development in animal models modifies the expression of genes involved in organ development, branching morphogenesis, and regulation of inflammation process [91]. Therefore, several respiratory parameters may be affected, including the reduction in lung volume, vital capacity and oxygen saturation, and increases in airway smooth muscle mass and airway contractility [92][93][94]. All of these changes alter normal lung physiology and might compromise the survival of the litters.…”