Does vitamin D influence pregnancy and fertility?

By (gynecologist), (gynaecologist), (gynecologist), (embryologist) and (psychologist).
Last Update: 12/05/2023

Vitamin D is commonly known to be related to bone and calcium metabolism. However, the presence of receptors for this vitamin in the ovary, uterus, and placenta has put it in the spotlight in relation to fertility and pregnancy.

Vitamin D deficiency in women of reproductive age is quite common. Serum vitamin D levels above 30 ng/ml are considered sufficient according to reference values. If vitamin D levels are between 21 and 29 ng/ml we speak of insufficiency, and if they are less than 20 ng/ml it is a deficiency.

Vitamin D and fertility

There are numerous studies linking vitamin D levels and reproductive capacity in women and men.

The effect of vitamin D on female and male fertility is detailed below.

Female fertility

According to several scientific studies, vitamin D improves the conditions for embryo implantation, due to its action on the endometrium. This is thanks to the anti-inflammatory and immunomodulatory effect of vitamin D on the immune system, as it is necessary for the embryo to be immunologically tolerated by the mother. In addition, this vitamin would produce the activation of genes related to implantation.

Similarly, an increase in progesterone secretion by ovarian granulosa cells has also been described. This hormone is essential for the pregnancy to evolve and be maintained.

However, vitamin D has been related to anti-mullerian hormone (AMH), a good marker of ovarian reserve, that is, the number of eggs a woman has at a given time.

In addition, vitamin D deficiency would affect endometriosis, polycystic ovarian syndrome (PCOS), uterine fibroids and increase miscarriages. All this causes difficulty in achieving a pregnancy and that this is evolutionary. Therefore, if vitamin D levels are adequate, a woman will have less risk of suffering from some of these gynecological conditions or will improve them and, therefore, will have a better prognosis at the time of seeking pregnancy.

However, more studies are still needed to provide a more conclusive result on the involvement of vitamin D in all these aspects of female fertility and pregnancy.

Male fertility

Vitamin D has been associated with sperm production (spermatogenesis) and maturation.

Adequate vitamin D levels appear to improve sperm motility in the seminogram. Another effect of vitamin D supplementation in males is that it may increase levels of testosterone, the male sex hormone produced by the testes.

However, as in the case of women, more conclusive studies are needed to corroborate the benefit of this vitamin on male fertility.

Vitamin D in pregnancy

Another relationship of vitamin D that has been studied has been with pregnancy. Vitamin D deficiency in pregnant women may lead to an increased risk of obstetric complications. Some of the problems a pregnant woman with low vitamin D levels may have are as follows:

In addition, a vitamin D deficiency in pregnant women would also generate a higher probability of suffering a miscarriage.

In the event of a lack of vitamin D, the specialist may advise supplementation. It is important that it is done under medical control with a dosage adjusted by the specialist.

Sources of vitamin D

Our body produces around 80-90% of vitamin D thanks to the effect of solar radiation on the skin. Therefore, the most advisable is a moderate daily exposure to the sun of about 15 minutes (avoiding the central hours of the day, which would be harmful to the skin) to maintain adequate levels of vitamin D.

However, the remaining 10-20% of vitamin D is acquired through the diet by eating certain foods rich in this vitamin, such as, for example:

  • Oily fish such as salmon.
  • Egg Yolk.
  • Liver.
  • Milk, cheese and yogurts, especially if fortified.
  • Mushroom.

When a person has low vitamin D levels, vitamin D supplementation is possible.

Women who are seeking to become pregnant, either naturally or through assisted reproduction treatment, can consult a specialist to find out their vitamin D levels.

Assisted procreation, as any other medical treatment, requires that you rely on the professionalism of the doctors and staff of the clinic you choose. Obviously, each clinic is different. Get now your Fertility Report, which will select several clinics for you out of the pool of clinics that meet our strict quality criteria. Moreover, it will offer you a comparison between the fees and conditions each clinic offers in order for you to make a well informed choice.

In the event that these amounts are lower than recommended, the specialist will prescribe vitamin supplements and adjust the dose to maintain adequate levels.

FAQs from users

What are the consequences of low vitamin D levels in pregnancy?

By Rubén Baltá I Arandes M.D. (gynecologist).

Vitamin D levels are of vital importance during pregnancy, as vitamin D deficiency can lead to an increased risk of preeclampsia, gestational diabetes, impaired immune system and low birth weight of the newborn.

Vitamin D has multiple and vital physiological functions such as regulation of metabolism, maintenance of bones and teeth, involvement in the proper functioning of the immune system and participation in the process of insulin secretion.

According to a Cochrane review, supplementation of pregnant women with vitamin D alone is likely to reduce the risk of pre-eclampsia, gestational diabetes and low birth weight, and may reduce the risk of severe postpartum hemorrhage. It is not well known whether it may influence the risk of preterm delivery at less than 37 weeks' gestation.

¿Afecta la vitamina D a la implantación embrionaria?

By Blanca Paraíso M.D., Ph.D., M.Sc. (gynecologist).

Although traditionally importance has been given only to the role of vitamin D in bone health, its possible role in fertility is gaining increasing interest. This vitamin has receptors throughout the body, including the ovary, endometrium and placenta, and has been linked to reproductive and obstetric outcomes.

Optimal vitamin D levels have been shown in several studies to improve the likelihood of pregnancy. However, the mechanism by which it increases the rate of gestation is still not very clear.

In a study carried out in recipients of donor eggs, in which it is assumed that all the embryos will be of good quality, it was observed that those patients with correct vitamin D levels had a greater chance of becoming pregnant. However, in another study performed with euploid embryo transfer (chromosomally healthy), this effect was not observed. Thus, although the evidence seems to indicate that vitamin D does improve endometrial receptivity, its role is probably more complex than it appears at first glance.

Another possible mechanism by which vitamin D could increase pregnancy rates is by improving oocyte quality. It has been shown that blood levels of vitamin D are proportional to follicular fluid levels, and it is thought that vitamin D may alleviate ovarian aging, although it has not been studied directly in oocytes.

Does vitamin D influence IVF treatments?

By Silvia Azaña Gutiérrez B.Sc., M.Sc. (embryologist).

It has been shown that women with adequate vitamin D levels have a higher probability of success after IVF treatment than women with a deficiency. However, other studies have not observed this relationship, so more studies are needed to support or rule out the usefulness of vitamin D supplementation in assisted reproduction treatment patients with a deficiency.

Do I need vitamin D supplements during pregnancy?

By Silvia Azaña Gutiérrez B.Sc., M.Sc. (embryologist).

The decision whether or not to administer vitamin D during pregnancy will be made by the physician based on the woman's vitamin D levels.

A systematic review found that vitamin D could reduce the risk of low birth weight and preterm delivery, while if given together with calcium it would reduce the risk of preeclampsia. However, the latter combination would increase the risk of preterm delivery.

Despite this, it was concluded that there is not enough evidence to give vitamin D supplements to all pregnant women in order to improve obstetric and neonatal complications.

Does vitamin D level matter for egg preservation?

By Katharina Spies M.D. (gynaecologist).

In summary, while vitamin D may play a role in egg preservation and fertility in general, it is essential to understand that this relationship is complex and that there is no one-size-fits-all solution. Consultation with a fertility specialist and individualized assessment are critical to address each woman's reproductive health needs.
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What is the relationship between systemic lupus erythematosus and vitamin D?

By Silvia Azaña Gutiérrez B.Sc., M.Sc. (embryologist).

Vitamin D deficiency is more common in people affected by this pathology than in healthy individuals. A lower sun exposure due to the photosensitivity of these patients, and an inability to produce active vitamin D due to renal dysfunction, could explain these findings.

Regarding vitamin D supplementation in these patients, for its immunomodulatory effect, there are contradictory results. While some studies have found no clear relationship in disease activity and serology with vitamin D supplementation, other studies have described a reduction in disease activity due to an immunosuppressive and anti-inflammatory effect.

If you are interested in fertility and nutrition, we recommend you visit this article: What are the types of foods that promote female fertility?

On the other hand, we have mentioned that vitamin D levels can improve sperm motility. For more information on this topic, you can visit this article: What are normal values in sperm motility analysis?

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Blomberg Jensen M, Bjerrum PJ, Jessen TE, et al. Vitamin D is positively associated with sperm motility and increases intracellular calcium in human spermatozoa. Hum Reprod. Jun 2011;26(6):1307-17.

Chen Y, Zhi X. Roles of Vitamin D in Reproductive Systems and Assisted Reproductive Technology. Endocrinology, April 2020; 161(4):1–12

Fichera M, Török P, Tesarik J, et al. Vitamin D, reproductive disorders and assisted reproduction: evidences and perspectives. Int J Food Sci Nutr. 2020;71(3):276–285.

FAQs from users: 'What are the consequences of low vitamin D levels in pregnancy?', '¿Afecta la vitamina D a la implantación embrionaria?', 'Does vitamin D influence IVF treatments?', 'Do I need vitamin D supplements during pregnancy?', 'Does vitamin D level matter for egg preservation?' and 'What is the relationship between systemic lupus erythematosus and vitamin D?'.

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Authors and contributors

 Blanca Paraíso
Blanca Paraíso
M.D., Ph.D., M.Sc.
Bachelor's Degree in Medicine and Ph.D from the Complutense University of Madrid (UCM). Postgraduate Course in Statistics of Health Sciences. Doctor specialized in Obstetrics & Gynecology, and Assisted Procreation. More information about Blanca Paraíso
License: 454505579
 Katharina  Spies
Katharina Spies
Katharina Spies has a medical degree from a German university and is a native German speaker. In addition, she speaks other languages such as English, Spanish and French, among others. Currently, Dr. Spies is the medical director of the Vida Fertility clinic in Madrid. More information about Katharina Spies
Licence: 282867990
 Rubén  Baltá I Arandes
Rubén Baltá I Arandes
Dr. Rubén Baltá has a degree in Medicine and Surgery from the Autonomous University of Barcelona and a postgraduate specialization in Esthetic and Functional Gynecology and Women's Cosmetic Genital Surgery from the University of Barcelona. More information about Rubén Baltá I Arandes
Medical licence: 070709574
 Silvia Azaña Gutiérrez
Silvia Azaña Gutiérrez
B.Sc., M.Sc.
Graduate in Health Biology from the University of Alcalá and specialized in Clinical Genetics from the same university. Master in Assisted Reproduction by the University of Valencia in collaboration with IVI clinics. More information about Silvia Azaña Gutiérrez
License: 3435-CV
Adapted into english by:
 Cristina  Algarra Goosman
Cristina Algarra Goosman
B.Sc., M.Sc.
Graduated in Psychology by the University of Valencia (UV) and specialized in Clinical Psychology by the European University Center and specific training in Infertility: Legal, Medical and Psychosocial Aspects by University of Valencia (UV) and ADEIT.
More information about Cristina Algarra Goosman
Member number: CV16874

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