Vitamin D - Pregnancy and Childbirth

Vitamin D or Sunshine Vitamin can be produced by the exposure of the skin to UV rays of the sun and through diet. Though diet plays a minor role in the production of vitamin D but consuming supplements can definitely increase the levels of the sunshine vitamin. Now many people suffer from vitamin D deficiency. Physiologically the need for vitamin D is very high for both pregnant and lactating mothers. Recently, the medical and research fraternity is showing a lot of interest in the study of how vitamin D is directly linked with pregnancy.

There is definitely a link between vitamin D and perinatal health outcome. Rachitic pelvis is a very common obstetric problem in the recent years and it has given rise to caesarian section birth proccedures. In the 1930s studies revealed that Vitamin D deficiency can also lead to uterine inertia, underlining the importance of vitamin D in maintaining a healthy reproductive system. Association between childhood rickets, risk of respiratory troubles, pneumonia and TB was proved long back.

But now the connection between vitamin D and immunity has been established clearly.

How Vitamin D is Produced and Utilised by the Body

After Vitamin D3 is produced by the body it is transported to the liver for hydroxylation to 25(OH)D, the form in which vitamin D is circulated in the body and measured. Then 25(OH)D reaches the kidney where it is again transformed into active hormonal form of vitamin D- 1,25(OH)2D.

The maternal 25(OH)D crosses the placenta easily. There are Vitamin D receptors or VDR in the placenta which produces enzyme CYP27B1 that converts 25(OH)D in its active form.

The reason why vitamin D is vital for pregnant mothers are

Levels of 1,25(OH) 2D levels don't correlate with 25 hydroxy vitamin D concentrations. The increased rate of intestinal calcium absorption, the rise in the demand of foetal calcium by

250mg/day in the third trimester and the rise in the count of active metabolite.

Why Vitamin D is Essential for Pregnant Mothers

Vitamin D helps to maintain normal levels of calcium and phosphate that aids in bone mineralization, muscle contraction and proper functioning of the nervous system and cells. Vitamin D deficiency can result in neonatal hypocalcemia and rickets in newborns so adequate vitamin D levels in pregnant mothers is essential. In places where vitamin D deficiency is bound to happen, children are often born with rickets.

Since breast milk is a poor source of vitamin D, so both expecting and lactating mothers should make it a point to maintain a proper vitamin D status during their pregnancy to avoid rickets during early infancy.

Speaking biologically, or scientifically there are several ways through which vitamin D can influence placental, foetal and maternal health during pregnancy. For instance-

Vitamin D has immune-modulating properties which help to develop maternal immune- response to placenta.

Vitamin D regulates the main genes that help in proper implantation of the placenta

Vitamin D directly help in the production of anti-microbial peptides like cathelicidin The peptides are produced when 'up- regulated' Vitamin D receptors are activated. The active form of Vitamin D or 25(OH)D is used as a substrate for the production of the peptides in the placenta. The anti-microbial peptide helps to prevent infection during pregnancy and early infancy.

Vitamin D in its active form regulates the effects of human chorionic gonadotropin (HCG) in syncytiotrophoblasts and stimulates the production of sex steroids.

Vitamin D also plays a vital role in glucose and insulin metabolism that regulate the amount of energy the foetus recieves.

Vitamin D helps in musculoskeletal growth.

Intake of vitamin D supplements regularly during pregnancy not only improves the maternal 25(OH)D levels, but also reduces the risk of low birthwieght by 60%.

Vitamin D deficiency can also influence infant mortality and prevent infections that can lead to premature delivery.

It is important to maintain Vitamin D status during pregnancy so that the infant is born with a healthy birthweight. Proper vitamin D levels also ensures healthy growth in infants.