Vitamin D may prevent COVID-19 induced pregnancy complication.

SARS-CoV-2 enters target cells via the ACE2 receptor and downregulates it. ACE2 exhibits high catalytic activity to produce Angiotensin 1-7 (Ang-1-7), which has a vasodilator effect and also inactivates the vasoconstrictor Angiotensin II. In normal pregnancy ACE2 expression is raising in the uterus and placenta. Ang-1-7 levels in plasma are significantly higher in third-trimester pregnant women when compared to non-pregnant women. This may be contributing to systemic vasodilation and reduced blood pressure and modulating hemodynamics during pregnancy. Interestingly, Ang-1-7 plasma levels are lower in pregnancies complicated by pre-eclampsia than normal pregnancies. COVID-19 infection increased the inflammatory cytokines and reduced ACE2 level. This may lead to pre-eclampsia or hypertensive pregnancies, then increasing the perinatal and maternal mortality and morbidity. Vitamin D increased ACE2 expression and Ang-1-7 plasma levels and also decreased Ang II level in plasma. Moreover, Vitamin D reduced the inflammatory cytokine storm. So, Vitamin D supplementation can prevent the risk of preeclampsia or hypertension in pregnant women with COVID-19.