Vitamin D and Reproductive Health: Why You Need Your Levels Tested!
If there is one test I suggest to every single patient who is trying to conceive, who has experienced a miscarriage, or is looking to support a healthy pregnancy and post-partum period, that test is vitamin D.
Vitamin D is best known as the sunshine vitamin since we can create vitamin D in our skin when exposed to sunlight. It plays an essential role in the absorption of calcium, immune function, and the health of our bones.
An ever-expanding body of research now suggests that vitamin D is more a hormone that plays a fundamental role in all aspects of our fertility from supporting healthy ovulation, improving pregnancy rates, reducing miscarriage risk and even supporting mood in the post-partum period. Vitamin D receptors have been found on reproductive tissues including the ovary, the uterus, and the placenta (1).
Vitamin D & Fertility Outcomes
Did you know that vitamin D is found within the follicular fluid that surrounds an egg? Studies have found that women who have higher levels of vitamin D in both their blood and follicular fluid are significantly more likely to achieve a clinical pregnancy when going through IVF compared to those with lower levels (1). One study found that women with the highest vitamin D levels were almost 4x more likely to achieve clinical pregnancy compared to those with the lowest levels (1)!
Vitamin D & Miscarriage Risk
Research suggests that healthy vitamin D levels play a role in reducing miscarriage risk in those who are experiencing recurrent pregnancy loss, defined as two or more consecutive losses (3). The reasons why are still being uncovered, but likely have to do with the fact that vitamin D plays an essential role in regulating the immune system (3). Studies have found that women who have experienced recurrent pregnancy losses have higher rates of vitamin D deficiency and are more likely to have autoimmune conditions including Hashimoto's thyroid disease, anti-phospholipid syndrome and elevated anti-nuclear antibody (ANA) levels (3).
Vitamin D & Pregnancy Health
It’s been found that up to 40% of pregnant women are vitamin D deficient (4)! This is a concern since vitamin D deficiency in pregnancy has been associated with an increased risk of negative outcomes. This includes an increased risk of gestational diabetes (elevated blood sugar), an increased risk of pre-eclampsia (high blood pressure) and an increased risk of bacterial vaginosis infections (2). These conditions in turn can increase the risk of preterm birth. Getting vitamin D levels into the healthy range can reduce the risk of all of these important pregnancy outcomes.
Vitamin D & Post Partum Mood
The postpartum period, also known as the 4th trimester, is an often overlooked time within a women’s fertility journey even though it’s an incredibly important time for both physical and mental well-being. It’s estimated that 18% of women experience antenatal depression and 19% of women experience postpartum depression (5). We know that depression in pregnancy and postpartum are not only associated with poorer health outcomes for the mother but also can impact behavioural outcomes, mental and physical health in their children (5).
Research has found an association between vitamin D deficiency and both antenatal depression and postpartum depression (5). We know that vitamin D receptors are found throughout the human brain, and research suggests that vitamin D deficiency alters neurotransmitters that are involved in depressive symptoms (5).
Testing & Supplementing With Vitamin D
Vitamin D levels can be tested through a simple blood draw and a test called 25-OH vitamin D. Vitamin D testing is not currently covered by OHIP in the province of Ontario. Since deficiency is so common it’s assumed levels are low and the general public is advised to supplement.
Unfortunately, the recommended dose of vitamin D can vary drastically depending on blood levels and in many cases the 1,000 IU daily dose that is typically suggested leaves many patients deficient and still at risk for many of the outcomes listed above.
For this reason, I recommend testing vitamin D levels to make sure supplementation levels are appropriate and deficiencies are corrected as quickly as possible. Just as important, we also want to avoid too high vitamin D levels which can be toxic. Never take high-dose vitamin D without testing your levels and confirming safety.
Looking For More Fertility Support?
Understanding how to optimize your fertility, reduce miscarriage risk and support yourself for the healthiest pregnancy and postpartum period is incredibly important! Naturopathic medicine has many tools that can support you along your fertility journey. You can read more about our fertility approach here, and reach out to the clinic if you have any questions!
References:
Ozkan, S., Jindal, S., Greenseid, K., Shu, J., Zeitlian, G., Hickmon, C., & Pal, L. (2010). Replete vitamin D stores predict reproductive success following in vitro fertilization. Fertility And Sterility, 94(4), 1314-1319. doi: 10.1016/j.fertnstert.2009.05.019
Lerchbaum, E., & Obermayer-Pietsch, B. (2012). MECHANISMS IN ENDOCRINOLOGY: Vitamin D and fertility: a systematic review. European Journal Of Endocrinology, 166(5), 765-778. doi: 10.1530/eje-11-0984
Zhao, H., Wei, X., & Yang, X. (2021). A novel update on vitamin D in recurrent pregnancy loss (Review). Molecular Medicine Reports, 23(5). doi: 10.3892/mmr.2021.12021
Heyden, E., & Wimalawansa, S. (2018). Vitamin D: Effects on human reproduction, pregnancy, and fetal well-being. The Journal Of Steroid Biochemistry And Molecular Biology, 180, 41-50. doi: 10.1016/j.jsbmb.2017.12.011
Aghajafari, F., Letourneau, N., Mahinpey, N., Cosic, N., & Giesbrecht, G. (2018). Vitamin D Deficiency and Antenatal and Postpartum Depression: A Systematic Review. Nutrients, 10(4), 478. doi: 10.3390/nu10040478