The Vital Role of Vitamin D in Pregnancy | OBGYN Explains

role of vitamin d in pregnancyVitamin D is not a “true” vitamin because it can be synthesized through the skin. It is actually a steroid hormone – group of fat-soluble pro-hormones – that encourage the absorption and metabolism of calcium and phosphorus. Vitamin D is also important for facilitating normal immune system function, as well as the normal growth and development of teeth and bones.

Requirements for vitamin D are high at certain stages of the lifecycle, especially during infancy and pregnancy. It is essential to bone health, though recent studies suggest that it contributes to human health beyond the skeletal system.

Importance of Vitamin D in Pregnancy

Pregnancy and breastfeeding are a critical time for both the mother and child; when the mother is giving her infant all the building blocks that he/she needs to build a foundation for future cardiovascular health, bone health, glucose metabolism, immune function, brain development, and the prevention of brain disorders.

So, what does vitamin D have to do with it?

The human body synthesizes vitamin D when you expose your skin to optimal sunlight, consume fatty-fish or vitamin D fortified foods, or take quality vitamin D3 supplements.

The female reproductive system consists of billions of cells, each of which contains genetic codes and a receptor for vitamin D. These cells, including the breasts, vagina, decidua, placenta, uterus, fallopian tubes, and ovaries are chock-full with vitamin D receptors.

When you have sufficient amounts of vitamin D in your cells, the vitamin D binds with its receptor, regulating genes in your reproductive system. For instance, vitamin D pathway genes influence in utero fetal development. On the other hand, when the female system has insufficient activated vitamin D, the genes critical to complete fetal health and smooth pregnancy are not articulated.

Importance of Vitamin D for the Mother

Pregnant women with sufficient vitamin D intake can enjoy reduced risk of pregnancy complications, such as:

  • gestational diabetes mellitus
  • pre-eclampsia
  • preterm birth
  • Caesarian section

Unfortunately, many pregnant women have insufficient vitamin D blood serum levels.

According to recent findings in a 2014 Canadian study, low maternal vitamin D is associated with increased risk of adverse pregnancy outcomes. So, vitamin D supplementation is critical to optimize maternal and neonatal vitamin D levels.

Other studies suggest that maternal vitamin D helps to decrease labor pain, while ensuring that the baby gets enough vitamin D during breastfeeding.

Importance of Vitamin D for the Baby

Vitamin D is important for fetal cell and bone development. Medical studies have revealed that some seeds for disease are sown before birth, and insufficient vitamin D during pregnancy may be one of those seeds. So, children born to mothers with vitamin D deficiency are more likely to develop certain medical conditions, including soft bones (rickets or craniotabes), cardiovascular malformation, asthma, autism, and type 1 diabetes mellitus.


The important role of vitamin D for the health of mothers and babies cannot be overstated. Besides getting vitamin D from 10 minutes of sunlight and certain foods like sardines, salmon, shrimp, egg yolk, and fortified foods, you can also get it from supplementation to reach the daily intake recommendation of 6,000 IU for pregnant and breastfeeding women (IU – international units – per day), as per the Institute of Food and Agricultural Sciences (IFAS) reports.

Pregnant and worrying about going past your due date? Dr. Torbati explains.

What Happens If I Go Past My Due Date? | Obstetrics Physician Answers

what happens when going past due dateResearchers show that only four percent (one in 25) of babies are born on their exact due date. 20 percent of babies are born at 41 weeks or later, so there are quite a few mothers concerned about going past their due date.

Is it normal to go past the expected due date?

For starters, the World Health Organization (WHO) and the International Federation of Gynecology and Obstetrics (FIGO) define prolonged (post-term) pregnancy as a gestational period of 42 weeks or more (beyond 294 days) from the first day of the last menstrual period (LMP). The gestation period is usually adjusted during the course of your pregnancy to give a more accurate date of when delivery is expected.

The organizations suggest that close to 14 percent of pregnancies proceed beyond the 42 week mark, while 4 percent continue past 43 weeks.

In other words, it is common to go beyond your due date. Most babies arrive between week 37 and week 41 of pregnancy – which is within a week on either side of their likely due date. Most twins and triplets usually arrive before 37 weeks of pregnancy.

Risks of Prolonged Pregnancy

Pregnancies that go beyond the 42nd week have some increased risks, including the possibility of:

  • requiring forceps or vacuum to assist delivery
  • baby “breathing in” amniotic fluid matter leading to complications after birth
  • c-section
  • still birth

As more time passes, researchers show that more calcium gets deposited within the placenta – a process called calcification – that interferes with its function. This is likely what contributes to the risks of a prolonged pregnancy.

Post-term infants are also usually larger than term infants. Statistics show that between 2.5 and 10 percent of babies delivered after 42 weeks exceed 4,500 grams compared to 0.8 – 1 percent of babies delivered at 40 weeks. Larger or heavier babies have a greater risk of mechanical labor problems, such as shoulder dystocia, requiring c-section, prolonged labor, and cephaslopelvic disproportion.

When Induction is Offered

To avoid complications arising from a prolonged pregnancy, induction may be offered at 41 weeks, or between days 7 and 10 after your due date. That said, labor is only induced if the pregnancy was straightforward, and the cervix is ready.

If induction is not planned and the pregnancy continues, fetal surveillance is mandated, and may include any combination of biophysical profiles (BPP), non-stress testing (NST), or modified biophysical profiles (amniotic fluid volume).

Dr. Torbati is an obstetrician in Tarzana that specializes in all types of pregnancy options including high-risk pregnancy and pre-term delivery. For more information on pregnancy, obstetrics, or family planning, please contact our office @ (818) 575-6119 and our specialists will be happy to assist you with your questions.