Earlier this year the Journal of Steroid Biochemistry and Molecular Biology published a study from India looking at the expression of immune cells and regulatory enzymes of vitamin D in pregnant women:
Vijayendra chary A, Hemalatha R, Seshacharyulu M, Vasudeva murali M, Jayaprakash D, Dinesh kumar B. Reprint of “Vitamin D deficiency in pregnant women impairs regulatory T cell function”. J Steroid Biochem Mol Biol. 2015; http://dx.doi.org/10.1016/j.jsbmb.2015.01.026
Despite abundant tropical sunshine, 84% of pregnant women in India have a 25(OH)D level less than 22.5 ng/mL. This is thought to be due to the cultural practice of confining pregnant women to indoors and the veil worn by Muslim women.
Vitamin D deficiency in pregnant women has been linked to decreased lung function and an increased risk of atopic allergy in their children. Previous research has found a link between lower vitamin D levels and abnormal concentrations of immune cells. The markers of immune function measured in this study included:
A total of 153 women from rural and urban areas were included in the study. While visiting the hospital for prenatal checkups, the 25(OH)D levels of the women were measured and they were classified as either vitamin D sufficient, insufficient, or deficient. Vitamin D sufficiency was defined as a 25(OH)D level ≥30 ng/mL, insufficiency was defined as a level between 20 and 29 ng/mL, and deficiency was defined as ≤19 ng/mL.
Concentrations of Treg cells and CD23 and CD21 on the B cells were also measured. After delivery, the cord blood of their infants was analyzed for the concentration of 25(OH)D and these immune cells and receptors.
A representative sample of 8 women was selected from each group of the women (sufficient, insufficient, and deficient) to analyze the expression of mRNA expression of several vitamin D-related receptors and vitamin D regulatory enzymes in the placenta. Measurements included:
Here are the results of the study:
The lower Treg cell concentrations coupled with an increased expression of the CD21 and CD23 expression on B cells may indicate an increased susceptibility to allergic and autoimmune disorders.
The authors interpreted the increased expression of CYP2R1 and CYP24A1 with decreased CYP27B1 as the body’s attempt to increase the concentration of active vitamin D in a vitamin D deficient state. Previous research has linked lower VDBP levels to increased protection against the symptoms of vitamin D deficiency.
The authors concluded,
“Impaired maternal vitamin D during pregnancy may influence a spectrum of immune cells in the mother and placenta, which in turn may be linked to allergy and asthma in neonates. The role of vitamin D in immune function and inflammation in pregnant women must not be underestimated…..and supplementation in pregnant women must be considered.”