The Relationship Between Vitamin D and Pregnancy

Did you know that there's a relationship between vitamin D and pregnancy? Understand more about why you need to maintain optimal levels while pregnant.
The Relationship Between Vitamin D and Pregnancy
Silvia Zaragoza

Written and verified by the nutritionist Silvia Zaragoza.

Last update: 27 December, 2022

For some years now, low levels of vitamin D are being recorded in people during their annual or monthly blood tests. Although it’s clear that deficiency leads to bone and immune problems, experts have established a link between vitamin D and pregnancy.

Did you know that approximately 20 to 40 percent of pregnant women have insufficient values of this vitamin? This is sometimes a problem both for the mother and for the proper development of the fetus.

This vitamin is involved in the correct implantation of the fetus in the uterus. A deficiency increases the risk factor for preeclampsia and gestational diabetes, among other illnesses. Do you want to know more? Keep reading.

Vitamin D and women’s health

It’s a hormone that’s synthesized from the 7-dehydrocholesterol present in the skin when exposed to the sun’s ultraviolet rays. It’s also present in foods rich in fat, such as egg yolks, dairy products, and oily fish.

Plant and animals sources of vitamin D.

One of its functions is to promote intestinal calcium absorption to strengthen the bones. It’s also responsible for maintaining the integrity of the intestinal wall and activates defense cells to fight infections. It even stimulates the secretion of anti-inflammatory substances.

Among the main problems caused by vitamin D deficiencies are difficulties in becoming pregnant and the risk of miscarriages. It acts on the endometrium and favors embryo implantation without rejection. Something that research hasn’t yet demonstrated is its influence on the quality of eggs and sperm.

Vitamin D deficiency and pregnancy: preeclampsia

Vitamin D deficiency usually appears from the 20th week of pregnancy and presents itself in the form of high blood pressure (systolic above 140 mmHg and diastolic above 90 mmHg), sudden weight gain, fluid retention, and swelling of the feet.

This vitamin acts on the renin-angiotensin system, it prevents placental vasoconstriction and stimulates vascular smooth muscle and endothelial cell proliferation. In addition, there’s a decrease in urinary calcium excretion and an increase in parathormone (PTH) secretion. As a consequence, active vitamin D levels decrease.

Gestational diabetes

This type of diabetes gets its name from the fact that doctors usually diagnose it for the first time during pregnancy. It involves an increase in blood glucose due to a lack of insulin sensitivity. And, although there are several risk factors, it seems that insufficient levels of vitamin D can increase the risk by 39 percent.

In addition, when pregnant women maintain normal vitamin D levels, there’s a decrease in glycosylated hemoglobin, blood glucose, and insulin values. These findings indicate that insulin sensitivity improves markedly, although experts are unaware of the mechanisms involved. Nevertheless, they suspect that calcium has something to do with it.

Other complications

Studies have also shown that the risk of having a cesarean section is higher in women with a vitamin D deficiency. This is due to the uterine muscles and the subsequent issues they may have contracting. A deficiency also facilitates the recurrence of bacterial vaginosis and premature delivery. However, the results are controversial and more studies are necessary.

A pregnant woman standing in the sun by a pool.

In addition, experts believe that the correct levels of vitamin D prevent postpartum depression. This is because of its involvement in neuronal protection against oxidation and the synthesis of dopamine, which regulates mood. As for children with low vitamin D levels,  they tend to suffer from recurrent respiratory infections during the first five years of life.

Conclusion regarding vitamin D and pregnancy?

As you’ve seen, vitamin D is essential at any stage of life, especially during pregnancy. By maintaining good levels (40-60 ng/ml), you’ll help to avoid the risk of complications before, during, and after pregnancy, and your child will grow up healthy.

Also, the fact that you have good vitamin D levels will have an impact on your child’s vitamin D levels. And although exposure to sunlight for at least 15-20 minutes a day is recommended, that alone won’t be enough to reach values above 30 ng/ml.

Therefore, it’s always best to consult a doctor or health professional for advice on the dosage and brand of a supplement. It’s advisable to take it in the morning with a food rich in fat, such as virgin olive oil, a slice of cheese, or avocado.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Rodriguez, A; Santa Marina, L; Jimenez, A M; Esplugues, A; Ballester, F; Espada, M et al (2016) Vitamin D Status in Pregnancy and Determinants in a Southern European Cohort Study. Paediatr Perinat Epidemiol, 30(3): 217-28.
  • Akbari, S; Khodadadi, B; Yasin Ahmadi, S A; Abbaszadeh, S; Shahsavar, F (2018) Association of vitamin D level and vitamin D deficiency with risk of preeclampsia: A systematic review and updated meta-analysis. Taiwan J Obstet Gynecol, 57(2): 241-47.
  • Serrano-Díaz, N C; Gamboa-Delgado, E M; Domínguez-Urrego, C L; Vesga-Varela, A L; Serrano-Gómez, S E; Quintero-Lesmes, D C (2018) Vitamin D and risk of preeclampsia: A systematic review and meta-analysis. Biomedica, 38(S1): 43-53.
  • Khaing, W; Arj-Ong Vallibhakara, S; Tantrakul, V; Vallibhakara, O; Rattanasiri, S; McEvoy, M et al (2017) Calcium and Vitamin D Supplementation for Prevention of Preeclampsia: A Systematic Review and Network Meta-Analysis. Nutrients, 9(10): 1141.
  • Hu, L; Zhang, Y; Wang, X; You, L; Xu, P; Cui, X et al (2018) Maternal Vitamin D Status and Risk of Gestational Diabetes: a Meta-Analysis. Cell Physiol Biochem, 45(1): 291-300.
  • Ojo, O; Weldon, S M; Thompson, T; Vargo, E J (2019) The Effect of Vitamin D Supplementation on Glycaemic Control in Women with Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Int J Environ Res Public Helath, 16(10): 1716. 
  • Rodríguez-Dehli, A. C., Riaño Galán, I., Fernández-Somoano, A., Navarrete-Muñoz, E. M., Espada, M., Vioque, J., & Tardón, A. (2015). Prevalencia de deficiencia e insuficiencia de vitamina D y factores asociados en mujeres embarazadas del norte de España. Nutricion Hospitalaria31(4), 1633-1640.
  • Mansur J. Vitamina D en pediatría, embarazo y lactancia. Arch Argent Pediatr 2018;116(4):286-290.[internet] Disponible en: [acceso julio 2021]

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.